| Monday, April 4 |
| » Defeated Mariners (0-1), 4-1 | Oakland-Alameda County Stadium (1-0) | 1-0 | |
| » W: Dave Stewart (1-0) L: Mark Langston (0-1) S: Dennis Eckersley (1) | First | -- |
| Tuesday, April 5 |
| » Defeated Mariners (0-2), 6-0 | Oakland-Alameda County Stadium (2-0) | 2-0 | Won 2 |
| » W: Bob Welch (1-0) L: Mike Moore (0-1) S: Dennis Eckersley (2) | First | -- |
| Wednesday, April 6 |
| » Lost to Mariners (1-2), 6-5 | Oakland-Alameda County Stadium (2-1) | 2-1 | |
| » W: Bill Swift (1-0) L: Gene Nelson (0-1) S: Julio Solano (1) | First | -- |
| Friday, April 8 |
| » Defeated Angels (1-3), 8-2 | Anaheim Stadium (1-0) | 3-1 | |
| » W: Storm Davis (1-0) L: Kirk McCaskill (0-1) S: Eric Plunk (1) | First | -- |
| » Major-league debuts: Doug Jennings (Athletics) |
| Saturday, April 9 |
| » Defeated Angels (1-4), 8-6 | Anaheim Stadium (2-0) | 4-1 | Won 2 |
| » W: Dave Stewart (2-0) L: Donnie Moore (1-1) S: Dennis Eckersley (3) | First | -- |
| Sunday, April 10 |
| » Lost to Angels (2-4), 6-4 | Anaheim Stadium (2-1) | 4-2 | |
| » W: Willie Fraser (1-0) L: Bob Welch (1-1) S: De Wayne Buice (1) | First | -- |
| Tuesday, April 12 |
| » Lost to Mariners (4-3), 6-4 | Kingdome (0-1) | 4-3 | Lost 2 |
| » W: Steve Trout (1-0) L: Gene Nelson (0-2) S: Jerry Reed (1) | First | -- |
| Former Athletic Frank Skaff dies in Towson, MD at the age of 78. |
| Wednesday, April 13 |
| » Defeated Mariners (4-4), 12-7 | Kingdome (1-1) | 5-3 | |
| » W: Steve Ontiveros (1-0) L: Mike Campbell (0-1) S: Rick Honeycutt (1) | First | -- |
| Thursday, April 14 |
| » Defeated Mariners (4-5), 5-4 | Kingdome (2-1) | 6-3 | Won 2 |
| » W: Dave Stewart (3-0) L: Jerry Reed (1-1) S: Dennis Eckersley (4) | First | -- |
| Friday, April 15 |
| » Lost to White Sox (4-5), 11-3 | Oakland-Alameda County Stadium (2-2) | 6-4 | |
| » W: Ricky Horton (2-1) L: Bob Welch (1-2) | Second | ½ out |
| Saturday, April 16 |
| » Lost to White Sox (5-5), 5-1 | Oakland-Alameda County Stadium (2-3) | 6-5 | Lost 2 |
| » W: Melido Perez (1-0) L: Storm Davis (1-1) S: Bobby Thigpen (2) | Second | ½ out |
| Sunday, April 17 |
| » Lost to White Sox (6-5), 7-6 | Oakland-Alameda County Stadium (2-4) | 6-6 | Lost 3 |
| » W: Jack McDowell (1-1) L: Steve Ontiveros (1-1) S: Bobby Thigpen (3) | Second | ½ out |
| Monday, April 18 |
| » Defeated Angels (6-6), 5-4 | Oakland-Alameda County Stadium (3-4) | 7-6 | |
| » W: Eric Plunk (1-0) L: De Wayne Buice (0-2) S: Dennis Eckersley (5) | Second | ½ out |
| Tuesday, April 19 |
| » Defeated Angels (6-7), 8-3 | Oakland-Alameda County Stadium (4-4) | 8-6 | Won 2 |
| » W: Dave Stewart (4-0) L: Chuck Finley (1-2) S: Dennis Eckersley (6) | Second | ½ out |
| Wednesday, April 20 |
| » Defeated Angels (6-8), 9-8 | Oakland-Alameda County Stadium (5-4) | 9-6 | Won 3 |
| » W: Gene Nelson (1-2) L: Donnie Moore (1-2) | First | -- |
| Thursday, April 21 |
| » Defeated White Sox (8-7), 6-3 | Comiskey Park I (1-0) | 10-6 | Won 4 |
| » W: Gene Nelson (2-2) L: Bill Long (0-1) S: Dennis Eckersley (7) | First | -- |
| Friday, April 22 |
| » Lost to White Sox (9-7), 7-5 | Comiskey Park I (1-1) | 10-7 | |
| » W: John Pawlowski (1-0) L: Eric Plunk (1-1) | First | -- |
| Saturday, April 23 |
| » Defeated White Sox (9-8), 3-2 | Comiskey Park I (2-1) | 11-7 | |
| » W: Dave Stewart (5-0) L: John Davis (1-1) | First | -- |
| Sunday, April 24 |
| » Defeated White Sox (9-9), 5-3 | Comiskey Park I (3-1) | 12-7 | Won 2 |
| » W: Bob Welch (2-2) L: Ricky Horton (2-3) S: Dennis Eckersley (8) | First | -- |
| Tuesday, April 26 |
| » Defeated Blue Jays (9-9), 6-1 | Exhibition Stadium (1-0) | 13-7 | Won 3 |
| » W: Storm Davis (2-1) L: Dave Stieb (1-3) S: Dennis Eckersley (9) | First | -- |
| Wednesday, April 27 |
| » Defeated Blue Jays (9-10), 5-3 | Exhibition Stadium (2-0) | 14-7 | Won 4 |
| » W: Curt Young (1-0) L: Mike Flanagan (2-1) S: Rick Honeycutt (2) | First | -- |
| Thursday, April 28 |
| » Defeated Blue Jays (9-11), 6-2 | Exhibition Stadium (3-0) | 15-7 | Won 5 |
| » W: Dave Stewart (6-0) L: Todd Stottlemyre (0-2) S: Rick Honeycutt (3) | First | -- |
| Saturday, April 30 |
| » Defeated Indians (16-6), 11-3 | Cleveland Stadium (1-0) | 16-7 | Won 6 |
| » W: Bob Welch (3-2) L: Rich Yett (2-1) S: Gene Nelson (1) | First | -- |
| Sunday, May 1 |
| » Defeated Indians (16-7), 8-4 | Cleveland Stadium (2-0) | 17-7 | Won 7 |
| » W: Eric Plunk (2-1) L: Doug Jones (0-1) | First | -- |
| Monday, May 2 |
| » Defeated Tigers (14-9), 4-2 | Tiger Stadium (1-0) | 18-7 | Won 8 |
| » W: Curt Young (2-0) L: Mike Henneman (0-1) S: Dennis Eckersley (10) | First | -- |
| Tuesday, May 3 |
| » Defeated Tigers (14-10), 8-2 | Tiger Stadium (2-0) | 19-7 | Won 9 |
| » W: Dave Stewart (7-0) L: Frank Tanana (5-1) | First | -- |
| Wednesday, May 4 |
| » Defeated Blue Jays (11-15), 3-2 | Oakland-Alameda County Stadium (6-4) | 20-7 | Won 10 |
| » W: Bob Welch (4-2) L: Jim Clancy (1-3) S: Dennis Eckersley (11) | First | -- |
| Thursday, May 5 |
| » Defeated Blue Jays (11-16), 8-5 | Oakland-Alameda County Stadium (7-4) | 21-7 | Won 11 |
| » W: Eric Plunk (3-1) L: Jose Nunez (0-1) | First | -- |
| Saturday, May 7 |
| » Defeated Indians (17-11), 14-3 | Oakland-Alameda County Stadium (8-4) | 22-7 | Won 12 |
| » W: Storm Davis (3-1) L: Tom Candiotti (4-1) S: Gene Nelson (2) | First | -- |
| Sunday, May 8 |
| » Defeated Indians (17-12), 5-1 | Oakland-Alameda County Stadium (9-4) | 23-7 | Won 13 |
| » W: Dave Stewart (8-0) L: Greg Swindell (6-1) | First | -- |
| Monday, May 9 |
| » Defeated Tigers (18-12), 3-1 | Oakland-Alameda County Stadium (10-4) | 24-7 | Won 14 |
| » W: Bob Welch (5-2) L: Jack Morris (3-4) S: Dennis Eckersley (12) | First | -- |
| Tuesday, May 10 |
| » Lost to Tigers (19-12), 8-2 | Oakland-Alameda County Stadium (10-5) | 24-8 | |
| » W: Walt Terrell (1-0) L: Curt Young (2-1) | First | -- |
| Wednesday, May 11 |
| » Lost to Tigers (20-12), 8-4 | Oakland-Alameda County Stadium (10-6) | 24-9 | Lost 2 |
| » W: Willie Hernandez (3-1) L: Dennis Eckersley (0-1) | First | -- |
| Friday, May 13 |
| » Lost to Orioles (5-29), 4-1 | Memorial Stadium (0-1) | 24-10 | Lost 3 |
| » W: Jay Tibbs (2-0) L: Dave Stewart (8-1) S: Tom Niedenfuer (1) | First | -- |
| Saturday, May 14 |
| » Defeated Orioles (5-30), 8-0 | Memorial Stadium (1-1) | 25-10 | |
| » W: Bob Welch (6-2) L: Mike Boddicker (0-8) | First | -- |
| Sunday, May 15 |
| » Defeated Orioles (5-31), 7-4 | Memorial Stadium (2-1) | 26-10 | Won 2 |
| » W: Curt Young (3-1) L: Mark Williamson (1-2) S: Dennis Eckersley (13) | First | -- |
| Monday, May 16 |
| » Defeated Red Sox (19-15), 3-0 | Fenway Park (1-0) | 27-10 | Won 3 |
| » W: Storm Davis (4-1) L: Jeff Sellers (0-4) S: Dennis Eckersley (14) | First | -- |
| Tuesday, May 17 |
| » Defeated Red Sox (19-16), 12-7 | Fenway Park (2-0) | 28-10 | Won 4 |
| » W: Steve Ontiveros (2-1) L: Steve Ellsworth (1-5) S: Rick Honeycutt (4) | First | -- |
| Wednesday, May 18 |
| » Lost to Red Sox (20-16), 4-1 | Fenway Park (2-1) | 28-11 | |
| » W: Oil Can Boyd (5-2) L: Dave Stewart (8-2) S: Lee Smith (5) | First | -- |
| Friday, May 20 |
| » Defeated Yankees (25-14), 11-3 | Yankee Stadium (1-0) | 29-11 | |
| » W: Bob Welch (7-2) L: Tommy John (2-1) | First | -- |
| Saturday, May 21 |
| » Lost to Yankees (26-14), 3-2 | Yankee Stadium (1-1) | 29-12 | |
| » W: Rick Rhoden (2-3) L: Curt Young (3-2) S: Dave Righetti (7) | First | -- |
| Sunday, May 22 |
| » Lost to Yankees (27-14), 2-0 | Yankee Stadium (1-2) | 29-13 | Lost 2 |
| » W: John Candelaria (6-2) L: Storm Davis (4-2) | First | -- |
| Monday, May 23 |
| » Lost to Orioles (9-34), 7-3 | Oakland-Alameda County Stadium (10-7) | 29-14 | Lost 3 |
| » W: Mike Boddicker (1-8) L: Dave Stewart (8-3) S: Tom Niedenfuer (4) | First | -- |
| Tuesday, May 24 |
| » Defeated Orioles (9-35), 6-0 | Oakland-Alameda County Stadium (11-7) | 30-14 | |
| » W: Steve Ontiveros (3-1) L: Jay Tibbs (2-1) | First | -- |
| Wednesday, May 25 |
| » Defeated Orioles (9-36), 8-1 | Oakland-Alameda County Stadium (12-7) | 31-14 | Won 2 |
| » W: Bob Welch (8-2) L: Mark Williamson (1-4) | First | -- |
| Former Athletic Charlie Perkins dies in Salem, OR at the age of 83. |
| Friday, May 27 |
| » Defeated Red Sox (23-20), 3-2 | Oakland-Alameda County Stadium (13-7) | 32-14 | Won 3 |
| » W: Curt Young (4-2) L: Bruce Hurst (6-2) S: Dennis Eckersley (15) | First | -- |
| Saturday, May 28 |
| » Defeated Red Sox (23-21), 7-5 | Oakland-Alameda County Stadium (14-7) | 33-14 | Won 4 |
| » W: Rick Honeycutt (1-0) L: Dennis Lamp (1-1) S: Dennis Eckersley (16) | First | -- |
| Sunday, May 29 |
| » Defeated Red Sox (23-22), 5-4 | Oakland-Alameda County Stadium (15-7) | 34-14 | Won 5 |
| » W: Gene Nelson (3-2) L: Jeff Sellers (0-5) S: Eric Plunk (2) | First | -- |
| Monday, May 30 |
| » Defeated Yankees (32-16), 3-2 | Oakland-Alameda County Stadium (16-7) | 35-14 | Won 6 |
| » W: Dennis Eckersley (1-1) L: Steve Shields (0-2) | First | -- |
| Tuesday, May 31 |
| » Lost to Yankees (33-16), 5-0 | Oakland-Alameda County Stadium (16-8) | 35-15 | |
| » W: Neil Allen (2-0) L: Steve Ontiveros (3-2) | First | -- |
| Wednesday, June 1 |
| » Defeated Yankees (33-17), 4-3 | Oakland-Alameda County Stadium (17-8) | 36-15 | |
| » W: Gene Nelson (4-2) L: Charles Hudson (4-2) S: Dennis Eckersley (17) | First | -- |
| Friday, June 3 |
| » Defeated Twins (26-24), 8-5 | Hubert H. Humphrey Metrodome (1-0) | 37-15 | Won 2 |
| » W: Dave Stewart (9-3) L: Les Straker (2-3) S: Dennis Eckersley (18) | First | -- |
| Saturday, June 4 |
| » Defeated Twins (26-25), 6-4 | Hubert H. Humphrey Metrodome (2-0) | 38-15 | Won 3 |
| » W: Storm Davis (5-2) L: Bert Blyleven (3-6) S: Dennis Eckersley (19) | First | -- |
| Sunday, June 5 |
| » Lost to Twins (27-25), 4-3 | Hubert H. Humphrey Metrodome (2-1) | 38-16 | |
| » W: Keith Atherton (4-1) L: Bob Welch (8-3) S: Jeff Reardon (14) | First | -- |
| Monday, June 6 |
| » Lost to Royals (28-28), 2-0 | Royals Stadium (0-1) | 38-17 | Lost 2 |
| » W: Steve Farr (2-0) L: Steve Ontiveros (3-3) S: Jerry Don Gleaton (2) | First | -- |
| Tuesday, June 7 |
| » Lost to Royals (29-28), 6-0 | Royals Stadium (0-2) | 38-18 | Lost 3 |
| » W: Ted Power (3-1) L: Curt Young (4-3) | First | -- |
| Wednesday, June 8 |
| » Lost to Royals (30-28), 5-4 | Royals Stadium (0-3) | 38-19 | Lost 4 |
| » W: Bret Saberhagen (8-5) L: Dave Stewart (9-4) S: Jeff Montgomery (1) | First | -- |
| Thursday, June 9 |
| » Lost to Rangers (29-29), 5-2 | Arlington Stadium (0-1) | 38-20 | Lost 5 |
| » W: Jeff Russell (5-0) L: Storm Davis (5-3) | First | -- |
| Friday, June 10 |
| » Defeated Rangers (29-30), 7-6 | Arlington Stadium (1-1) | 39-20 | |
| » W: Eric Plunk (4-1) L: Mitch Williams (1-2) S: Dennis Eckersley (20) | First | -- |
| Saturday, June 11 |
| » Defeated Rangers (29-31), 13-4 | Arlington Stadium (2-1) | 40-20 | Won 2 |
| » W: Greg Cadaret (1-0) L: Jose Guzman (6-5) | First | -- |
| Sunday, June 12 |
| » Lost to Rangers (30-31), 3-2 | Arlington Stadium (2-2) | 40-21 | |
| » W: Charlie Hough (6-7) L: Dave Stewart (9-5) | First | -- |
| Tuesday, June 14 |
| » Lost to Royals (34-29), 2-1 | Oakland-Alameda County Stadium (17-9) | 40-22 | Lost 2 |
| » W: Bret Saberhagen (9-5) L: Greg Cadaret (1-1) S: Gene Garber (6) | First | -- |
| Wednesday, June 15 |
| » Lost to Royals (35-29), 2-0 | Oakland-Alameda County Stadium (17-10) | 40-23 | Lost 3 |
| » W: Charlie Leibrandt (3-9) L: Bob Welch (8-4) | First | -- |
| Thursday, June 16 |
| » Lost to Royals (36-29), 9-5 | Oakland-Alameda County Stadium (17-11) | 40-24 | Lost 4 |
| » W: Mark Gubicza (9-5) L: Curt Young (4-4) | First | -- |
| Friday, June 17 |
| » Defeated Rangers (31-34), 7-6 | Oakland-Alameda County Stadium (18-11) | 41-24 | |
| » W: Rick Honeycutt (2-0) L: Dale Mohorcic (2-4) | First | -- |
| Saturday, June 18 |
| » Defeated Rangers (31-35), 2-1 | Oakland-Alameda County Stadium (19-11) | 42-24 | Won 2 |
| » W: Gene Nelson (5-2) L: Dale Mohorcic (2-5) | First | -- |
| Sunday, June 19 |
| » Lost to Rangers (32-35), 5-4 | Oakland-Alameda County Stadium (19-12) | 42-25 | |
| » W: Craig McMurtry (1-0) L: Rick Honeycutt (2-1) S: Mitch Williams (10) | First | -- |
| Monday, June 20 |
| » Defeated Brewers (36-33), 5-4 | County Stadium (1-0) | 43-25 | |
| » W: Eric Plunk (5-1) L: Chuck Crim (0-4) S: Dennis Eckersley (21) | First | -- |
| Tuesday, June 21 |
| » Defeated Brewers (36-34), 4-2 | County Stadium (2-0) | 44-25 | Won 2 |
| » W: Curt Young (5-4) L: Chris Bosio (6-8) S: Dennis Eckersley (22) | First | -- |
| Wednesday, June 22 |
| » Defeated Brewers (36-35), 6-2 | County Stadium (3-0) | 45-25 | Won 3 |
| » W: Dave Stewart (10-5) L: Don August (3-2) | First | -- |
| Friday, June 24 |
| » Lost to Twins (39-30), 11-5 | Oakland-Alameda County Stadium (19-13) | 45-26 | |
| » W: Keith Atherton (5-2) L: Gene Nelson (5-3) | First | -- |
| Saturday, June 25 |
| » Defeated Twins (39-31), 4-3 | Oakland-Alameda County Stadium (20-13) | 46-26 | |
| » W: Bob Welch (9-4) L: Allan Anderson (4-5) S: Dennis Eckersley (23) | First | -- |
| » Major-league debuts: Kelvin Torve (Twins) |
| Sunday, June 26 |
| » Lost to Twins (40-31), 11-0 | Oakland-Alameda County Stadium (20-14) | 46-27 | |
| » W: Charlie Lea (4-3) L: Curt Young (5-5) S: Juan Berenguer (1) | First | -- |
| » Lost to Twins (41-31), 5-0 | Oakland-Alameda County Stadium (20-15) | 46-28 | Lost 2 |
| » W: Frank Viola (12-2) L: Dave Stewart (10-6) S: Keith Atherton (3) | First | -- |
| Monday, June 27 |
| » Defeated Brewers (37-38), 5-4 | Oakland-Alameda County Stadium (21-15) | 47-28 | |
| » W: Dennis Eckersley (2-1) L: Dan Plesac (1-1) | First | -- |
| Tuesday, June 28 |
| » Lost to Brewers (38-38), 4-1 | Oakland-Alameda County Stadium (21-16) | 47-29 | |
| » W: Don August (4-2) L: Storm Davis (5-4) | First | -- |
| Wednesday, June 29 |
| » Defeated Brewers (38-39), 7-2 | Oakland-Alameda County Stadium (22-16) | 48-29 | |
| » W: Bob Welch (10-4) L: Bill Wegman (6-6) | First | -- |
| Friday, July 1 |
| » Defeated Blue Jays (39-41), 2-1 | Exhibition Stadium (4-0) | 49-29 | Won 2 |
| » W: Dave Stewart (11-6) L: Dave Stieb (10-5) S: Dennis Eckersley (24) | First | -- |
| Saturday, July 2 |
| » Defeated Blue Jays (39-42), 11-3 | Exhibition Stadium (5-0) | 50-29 | Won 3 |
| » W: Curt Young (6-5) L: Mike Flanagan (7-6) S: Gene Nelson (3) | First | -- |
| Sunday, July 3 |
| » Defeated Blue Jays (39-43), 9-8 | Exhibition Stadium (6-0) | 51-29 | Won 4 |
| » W: Todd Burns (1-0) L: John Cerutti (4-5) | First | -- |
| Monday, July 4 |
| » Defeated Indians (42-39), 4-2 | Cleveland Stadium (3-0) | 52-29 | Won 5 |
| » W: Greg Cadaret (2-1) L: Brad Havens (1-1) S: Dennis Eckersley (25) | First | -- |
| Tuesday, July 5 |
| » Lost to Indians (43-39), 3-0 | Cleveland Stadium (3-1) | 52-30 | |
| » W: Scott Bailes (7-7) L: Dave Stewart (11-7) | First | -- |
| » Lost to Indians (44-39), 4-2 | Cleveland Stadium (3-2) | 52-31 | Lost 2 |
| » W: Rick Rodriguez (1-1) L: Rich Bordi (0-1) S: Doug Jones (20) | First | -- |
| Wednesday, July 6 |
| » Lost to Indians (45-39), 8-6 | Cleveland Stadium (3-3) | 52-32 | Lost 3 |
| » W: Don Gordon (1-0) L: Rick Honeycutt (2-2) | First | -- |
| Thursday, July 7 |
| » Lost to Tigers (51-31), 8-1 | Tiger Stadium (2-1) | 52-33 | Lost 4 |
| » W: Jeff Robinson (10-3) L: Curt Young (6-6) | First | -- |
| Friday, July 8 |
| » Defeated Tigers (51-32), 3-2 | Tiger Stadium (3-1) | 53-33 | |
| » W: Storm Davis (6-4) L: Eric King (1-1) S: Dennis Eckersley (26) | First | -- |
| Saturday, July 9 |
| » Lost to Tigers (52-32), 4-3 | Tiger Stadium (3-2) | 53-34 | |
| » W: Frank Tanana (11-4) L: Bob Welch (10-5) S: Willie Hernandez (4) | First | -- |
| Sunday, July 10 |
| » Defeated Tigers (52-33), 8-2 | Tiger Stadium (4-2) | 54-34 | |
| » W: Dave Stewart (12-7) L: Walt Terrell (3-7) | First | -- |
| Thursday, July 14 |
| » Lost to Blue Jays (43-46), 7-1 | Oakland-Alameda County Stadium (22-17) | 54-35 | |
| » W: Mike Flanagan (9-6) L: Bob Welch (10-6) | First | -- |
| Friday, July 15 |
| » Lost to Blue Jays (44-46), 1-0 | Oakland-Alameda County Stadium (22-18) | 54-36 | Lost 2 |
| » W: Jimmy Key (6-1) L: Dave Stewart (12-8) | First | -- |
| Saturday, July 16 |
| » Defeated Blue Jays (44-47), 4-1 | Oakland-Alameda County Stadium (23-18) | 55-36 | |
| » W: Storm Davis (7-4) L: Dave Stieb (10-6) S: Dennis Eckersley (27) | First | -- |
| Sunday, July 17 |
| » Lost to Blue Jays (45-47), 9-6 | Oakland-Alameda County Stadium (23-19) | 55-37 | |
| » W: Duane Ward (6-0) L: Curt Young (6-7) S: Tom Henke (17) | First | -- |
| Monday, July 18 |
| » Defeated Indians (47-46), 7-2 | Oakland-Alameda County Stadium (24-19) | 56-37 | |
| » W: Todd Burns (2-0) L: Scott Bailes (7-9) | First | -- |
| Tuesday, July 19 |
| » Defeated Indians (47-47), 4-2 | Oakland-Alameda County Stadium (25-19) | 57-37 | Won 2 |
| » W: Bob Welch (11-6) L: Greg Swindell (10-9) S: Dennis Eckersley (28) | First | -- |
| » Defeated Indians (47-48), 9-6 | Oakland-Alameda County Stadium (26-19) | 58-37 | Won 3 |
| » W: Greg Cadaret (3-1) L: Don Gordon (2-1) S: Dennis Eckersley (29) | First | -- |
| Wednesday, July 20 |
| » Lost to Indians (48-48), 5-4 | Oakland-Alameda County Stadium (26-20) | 58-38 | |
| » W: John Farrell (10-6) L: Dave Stewart (12-9) S: Doug Jones (23) | First | -- |
| Friday, July 22 |
| » Defeated Tigers (55-38), 4-1 | Oakland-Alameda County Stadium (27-20) | 59-38 | |
| » W: Storm Davis (8-4) L: Jeff Robinson (11-4) S: Dennis Eckersley (30) | First | -- |
| Saturday, July 23 |
| » Defeated Tigers (55-39), 4-1 | Oakland-Alameda County Stadium (28-20) | 60-38 | Won 2 |
| » W: Todd Burns (3-0) L: Frank Tanana (11-6) S: Eric Plunk (3) | First | -- |
| Sunday, July 24 |
| » Defeated Tigers (55-40), 1-0 | Oakland-Alameda County Stadium (29-20) | 61-38 | Won 3 |
| » W: Bob Welch (12-6) L: Walt Terrell (4-8) | First | -- |
| Monday, July 25 |
| » Lost to Angels (48-50), 2-1 | Anaheim Stadium (2-2) | 61-39 | |
| » W: Kirk McCaskill (8-5) L: Dave Stewart (12-10) | First | -- |
| Tuesday, July 26 |
| » Defeated Angels (48-51), 6-2 | Anaheim Stadium (3-2) | 62-39 | |
| » W: Storm Davis (9-4) L: Mike Witt (7-10) | First | -- |
| Wednesday, July 27 |
| » Lost to Angels (49-51), 9-8 | Anaheim Stadium (3-3) | 62-40 | |
| » W: Donnie Moore (4-2) L: Jim Corsi (0-1) | First | -- |
| Friday, July 29 |
| » Lost to Mariners (40-62), 5-3 | Kingdome (2-2) | 62-41 | Lost 2 |
| » W: Mike Jackson (6-2) L: Dennis Eckersley (2-2) | First | -- |
| Saturday, July 30 |
| » Defeated Mariners (40-63), 5-2 | Kingdome (3-2) | 63-41 | |
| » W: Dave Stewart (13-10) L: Mike Moore (4-12) | First | -- |
| Sunday, July 31 |
| » Defeated Mariners (40-64), 6-2 | Kingdome (4-2) | 64-41 | Won 2 |
| » W: Storm Davis (10-4) L: Scott Bankhead (5-5) S: Greg Cadaret (1) | First | -- |
| Monday, August 1 |
| » Defeated White Sox (46-59), 10-2 | Comiskey Park I (4-1) | 65-41 | Won 3 |
| » W: Todd Burns (4-0) L: Melido Perez (10-6) | First | -- |
| » Major-league debuts: Donn Pall (White Sox) |
| Tuesday, August 2 |
| » Lost to White Sox (47-59), 7-5 | Comiskey Park I (4-2) | 65-42 | |
| » W: Dave LaPoint (8-11) L: Steve Ontiveros (3-4) S: Bobby Thigpen (22) | First | -- |
| Wednesday, August 3 |
| » Defeated White Sox (47-60), 4-3 | Comiskey Park I (5-2) | 66-42 | |
| » W: Gene Nelson (6-3) L: Bobby Thigpen (5-6) S: Dennis Eckersley (31) | First | -- |
| Thursday, August 4 |
| » Defeated Mariners (41-67), 2-0 | Oakland-Alameda County Stadium (30-20) | 67-42 | Won 2 |
| » W: Dave Stewart (14-10) L: Mike Moore (4-13) | First | -- |
| Friday, August 5 |
| » Defeated Mariners (41-68), 4-1 | Oakland-Alameda County Stadium (31-20) | 68-42 | Won 3 |
| » W: Storm Davis (11-4) L: Scott Bankhead (5-6) S: Dennis Eckersley (32) | First | -- |
| Saturday, August 6 |
| » Defeated Mariners (41-69), 5-4 | Oakland-Alameda County Stadium (32-20) | 69-42 | Won 4 |
| » W: Gene Nelson (7-3) L: Mike Jackson (6-3) | First | -- |
| Sunday, August 7 |
| » Lost to Mariners (42-69), 12-7 | Oakland-Alameda County Stadium (32-21) | 69-43 | |
| » W: Mike Schooler (4-4) L: Eric Plunk (5-2) | First | -- |
| Monday, August 8 |
| » Defeated White Sox (49-63), 9-5 | Oakland-Alameda County Stadium (33-21) | 70-43 | |
| » W: Bob Welch (13-6) L: Bill Long (4-7) S: Dennis Eckersley (33) | First | -- |
| Tuesday, August 9 |
| » Defeated White Sox (49-64), 8-1 | Oakland-Alameda County Stadium (34-21) | 71-43 | Won 2 |
| » W: Dave Stewart (15-10) L: Jeff Bittiger (1-3) | First | -- |
| Wednesday, August 10 |
| » Defeated White Sox (49-65), 2-1 | Oakland-Alameda County Stadium (35-21) | 72-43 | Won 3 |
| » W: Greg Cadaret (4-1) L: Ricky Horton (6-10) | First | -- |
| Thursday, August 11 |
| » Defeated Angels (58-57), 7-2 | Oakland-Alameda County Stadium (36-21) | 73-43 | Won 4 |
| » W: Dennis Eckersley (3-2) L: Terry Clark (5-1) | First | -- |
| Friday, August 12 |
| » Defeated Angels (58-58), 4-0 | Oakland-Alameda County Stadium (37-21) | 74-43 | Won 5 |
| » W: Todd Burns (5-0) L: Chuck Finley (6-11) S: Greg Cadaret (2) | First | -- |
| Saturday, August 13 |
| » Defeated Angels (58-59), 6-2 | Oakland-Alameda County Stadium (38-21) | 75-43 | Won 6 |
| » W: Bob Welch (14-6) L: Stew Cliburn (4-1) S: Rick Honeycutt (5) | First | -- |
| Sunday, August 14 |
| » Lost to Angels (59-59), 6-4 | Oakland-Alameda County Stadium (38-22) | 75-44 | |
| » W: Mike Witt (9-11) L: Gene Nelson (7-4) S: Bryan Harvey (12) | First | -- |
| Tuesday, August 16 |
| » Defeated Orioles (39-79), 6-3 | Memorial Stadium (3-1) | 76-44 | |
| » W: Storm Davis (12-4) L: Jay Tibbs (4-10) S: Dennis Eckersley (34) | First | -- |
| Wednesday, August 17 |
| » Defeated Orioles (39-80), 10-4 | Memorial Stadium (4-1) | 77-44 | Won 2 |
| » W: Curt Young (7-7) L: Doug Sisk (3-3) S: Eric Plunk (4) | First | -- |
| Thursday, August 18 |
| » Lost to Orioles (40-80), 10-1 | Memorial Stadium (4-2) | 77-45 | |
| » W: Jeff Ballard (7-10) L: Bob Welch (14-7) | First | -- |
| Friday, August 19 |
| » Lost to Red Sox (68-53), 7-6 | Fenway Park (2-2) | 77-46 | Lost 2 |
| » W: Bob Stanley (5-1) L: Dave Stewart (15-11) | First | -- |
| Saturday, August 20 |
| » Lost to Red Sox (69-53), 7-5 | Fenway Park (2-3) | 77-47 | Lost 3 |
| » W: Jeff Sellers (1-6) L: Todd Burns (5-1) S: Lee Smith (19) | First | -- |
| Sunday, August 21 |
| » Defeated Red Sox (69-54), 5-4 | Fenway Park (3-3) | 78-47 | |
| » W: Rick Honeycutt (3-2) L: Bob Stanley (5-2) S: Dennis Eckersley (35) | First | -- |
| Monday, August 22 |
| » Defeated Yankees (66-56), 9-2 | Yankee Stadium (2-2) | 79-47 | Won 2 |
| » W: Curt Young (8-7) L: Charles Hudson (6-4) | First | -- |
| Tuesday, August 23 |
| » Lost to Yankees (67-56), 5-4 | Yankee Stadium (2-3) | 79-48 | |
| » W: Dave Righetti (5-3) L: Greg Cadaret (4-2) | First | -- |
| Wednesday, August 24 |
| » Lost to Yankees (68-56), 7-6 | Yankee Stadium (2-4) | 79-49 | Lost 2 |
| » W: Cecilio Guante (5-6) L: Gene Nelson (7-5) | First | -- |
| Friday, August 26 |
| » Defeated Orioles (44-83), 8-5 | Oakland-Alameda County Stadium (39-22) | 80-49 | |
| » W: Storm Davis (13-4) L: Jay Tibbs (4-12) S: Eric Plunk (5) | First | -- |
| Saturday, August 27 |
| » Defeated Orioles (44-84), 5-1 | Oakland-Alameda County Stadium (40-22) | 81-49 | Won 2 |
| » W: Todd Burns (6-1) L: Oswaldo Peraza (5-7) S: Greg Cadaret (3) | First | -- |
| Sunday, August 28 |
| » Lost to Orioles (45-84), 2-1 | Oakland-Alameda County Stadium (40-23) | 81-50 | |
| » W: Mark Williamson (4-5) L: Gene Nelson (7-6) S: Tom Niedenfuer (14) | First | -- |
| Monday, August 29 |
| » Defeated Red Sox (73-57), 3-1 | Oakland-Alameda County Stadium (41-23) | 82-50 | |
| » W: Bob Welch (15-7) L: Mike Boddicker (10-15) S: Dennis Eckersley (36) | First | -- |
| Tuesday, August 30 |
| » Defeated Red Sox (73-58), 1-0 | Oakland-Alameda County Stadium (42-23) | 83-50 | Won 2 |
| » W: Dave Stewart (16-11) L: Roger Clemens (15-10) | First | -- |
| Wednesday, August 31 |
| » Defeated Red Sox (73-59), 7-2 | Oakland-Alameda County Stadium (43-23) | 84-50 | Won 3 |
| » W: Storm Davis (14-4) L: Mike Smithson (6-5) | First | -- |
| Friday, September 2 |
| » Lost to Yankees (70-62), 4-1 | Oakland-Alameda County Stadium (43-24) | 84-51 | |
| » W: Tommy John (9-6) L: Curt Young (8-8) S: Dave Righetti (20) | First | -- |
| » Major-league debuts: Felix Jose (Athletics) |
| Saturday, September 3 |
| » Defeated Yankees (70-63), 5-4 | Oakland-Alameda County Stadium (44-24) | 85-51 | |
| » W: Eric Plunk (6-2) L: Dale Mohorcic (2-7) S: Dennis Eckersley (37) | First | -- |
| Sunday, September 4 |
| » Defeated Yankees (70-64), 11-2 | Oakland-Alameda County Stadium (45-24) | 86-51 | Won 2 |
| » W: Dave Stewart (17-11) L: Richard Dotson (9-9) | First | -- |
| » Major-league debuts: Lance Blankenship (Athletics) |
| Monday, September 5 |
| » Defeated Rangers (60-76), 11-4 | Arlington Stadium (3-2) | 87-51 | Won 3 |
| » W: Storm Davis (15-4) L: Paul Kilgus (11-13) | First | -- |
| Tuesday, September 6 |
| » Lost to Rangers (61-76), 3-1 | Arlington Stadium (3-3) | 87-52 | |
| » W: Charlie Hough (12-15) L: Todd Burns (6-2) S: Cecilio Guante (12) | First | -- |
| Former Athletic Lew Krausse dies in Sarasota, FL at the age of 77. |
| Wednesday, September 7 |
| » Defeated Rangers (61-77), 6-3 | Arlington Stadium (4-3) | 88-52 | |
| » W: Gene Nelson (8-6) L: Jose Guzman (11-11) S: Dennis Eckersley (38) | First | -- |
| Thursday, September 8 |
| » Defeated Royals (74-66), 5-1 | Royals Stadium (1-3) | 89-52 | Won 2 |
| » W: Curt Young (9-8) L: Bret Saberhagen (13-14) S: Dennis Eckersley (39) | First | -- |
| » Major-league debuts: Tom Gordon Mark Lee and Rey Palacios (Royals) |
| Friday, September 9 |
| » Defeated Royals (74-67), 14-6 | Royals Stadium (2-3) | 90-52 | Won 3 |
| » W: Dave Stewart (18-11) L: Jose DeJesus (0-1) S: Rick Honeycutt (6) | First | -- |
| » Major-league debuts: Jose DeJesus (Royals) |
| Saturday, September 10 |
| » Lost to Royals (75-67), 9-4 | Royals Stadium (2-4) | 90-53 | |
| » W: Charlie Leibrandt (11-12) L: Storm Davis (15-5) | First | -- |
| Sunday, September 11 |
| » Defeated Royals (75-68), 8-7 | Royals Stadium (3-4) | 91-53 | |
| » W: Dennis Eckersley (4-2) L: Steve Farr (5-3) | First | -- |
| Tuesday, September 13 |
| » Defeated Rangers (63-80), 2-1 | Oakland-Alameda County Stadium (46-24) | 92-53 | Won 2 |
| » W: Curt Young (10-8) L: Jose Guzman (11-12) S: Dennis Eckersley (40) | First | -- |
| » Major-league debuts: Kevin Reimer (Rangers) |
| Wednesday, September 14 |
| » Lost to Rangers (64-80), 9-1 | Oakland-Alameda County Stadium (46-25) | 92-54 | |
| » W: Kevin Brown (1-0) L: Dave Stewart (18-12) | First | -- |
| » Major-league debuts: Chad Kreuter (Rangers) |
| Thursday, September 15 |
| » Defeated Rangers (64-81), 6-2 | Oakland-Alameda County Stadium (47-25) | 93-54 | |
| » W: Todd Burns (7-2) L: Bobby Witt (6-10) | First | -- |
| Friday, September 16 |
| » Lost to Royals (79-68), 3-0 | Oakland-Alameda County Stadium (47-26) | 93-55 | |
| » W: Mark Gubicza (18-7) L: Bob Welch (15-8) | First | -- |
| Saturday, September 17 |
| » Defeated Royals (79-69), 3-2 | Oakland-Alameda County Stadium (48-26) | 94-55 | |
| » W: Eric Plunk (7-2) L: Tom Gordon (0-1) S: Dennis Eckersley (41) | First | -- |
| Sunday, September 18 |
| » Defeated Royals (79-70), 3-2 | Oakland-Alameda County Stadium (49-26) | 95-55 | Won 2 |
| » W: Greg Cadaret (5-2) L: Steve Farr (5-4) | First | -- |
| Monday, September 19 |