| Wednesday, January 8 |
| Future Cub Jeremi Gonzalez is born in Maracaibo, Venezuela. |
| Friday, March 28 |
| Future Cub Julio Zuleta is born in Panama City, Panama. |
| Monday, April 7 |
| » Major-league debuts: Jerry Remy (Angels) |
| Tuesday, April 8 |
| » Major-league debuts: Jim Umbarger (Rangers) Lyman Bostock (Twins) |
| Thursday, April 10 |
| » Lost to Pirates (1-0), 8-4 | Wrigley Field (0-1) | 0-1 | |
| » W: Dave Giusti (1-0) L: Ken Frailing (0-1) | Fifth | 1 out |
| Friday, April 11 |
| » Defeated Expos (1-3), 2-1 | Wrigley Field (1-1) | 1-1 | |
| » W: Ray Burris (1-0) L: Dennis Blair (0-1) | Third | 1 out |
| Saturday, April 12 |
| » Defeated Expos (1-4), 6-3 | Wrigley Field (2-1) | 2-1 | Won 2 |
| » W: Oscar Zamora (1-0) L: Dale Murray (0-2) | Third | ½ out |
| Sunday, April 13 |
| » Defeated Expos (1-5), 7-0 | Wrigley Field (3-1) | 3-1 | Won 3 |
| » W: Steve Stone (1-0) L: Steve Rogers (0-2) | Second | ½ out |
| Monday, April 14 |
| » Defeated Pirates (3-1), 4-2 | Three Rivers Stadium (1-0) | 4-1 | Won 4 |
| » W: Rick Reuschel (1-0) L: Bob Moose (0-1) S: Darold Knowles (1) | First | -- |
| Wednesday, April 16 |
| » Defeated Phillies (3-4), 9-3 | Veteran's Stadium (1-0) | 5-1 | Won 5 |
| » W: Bill Bonham (1-0) L: Steve Carlton (0-2) | First | -- |
| Thursday, April 17 |
| » Defeated Phillies (3-5), 10-9 | Veteran's Stadium (2-0) | 6-1 | Won 6 |
| » W: Ken Frailing (1-1) L: Wayne Twitchell (0-2) | First | -- |
| Saturday, April 19 |
| » Defeated Mets (2-6), 4-2 | Shea Stadium (1-0) | 7-1 | Won 7 |
| » W: Steve Stone (2-0) L: Tom Seaver (1-2) S: Darold Knowles (2) | First | -- |
| Sunday, April 20 |
| » Lost to Mets (3-6), 8-6 | Shea Stadium (1-1) | 7-2 | |
| » W: Jon Matlack (1-1) L: Rick Reuschel (1-1) S: Bob Apodaca (1) | First | -- |
| » Lost to Mets (4-6), 4-3 | Shea Stadium (1-2) | 7-3 | Lost 2 |
| » W: Randy Tate (1-0) L: Burt Hooton (0-1) S: Rick Baldwin (1) | First | -- |
| Tuesday, April 22 |
| » Lost to Phillies (6-5), 7-5 | Wrigley Field (3-2) | 7-4 | Lost 3 |
| » W: Wayne Twitchell (1-2) L: Bill Bonham (1-1) | First | -- |
| Wednesday, April 23 |
| » Defeated Phillies (6-6), 9-3 | Wrigley Field (4-2) | 8-4 | |
| » W: Ray Burris (2-0) L: Tom Underwood (2-1) S: Oscar Zamora (1) | First | -- |
| Thursday, April 24 |
| » Defeated Phillies (6-7), 4-1 | Wrigley Field (5-2) | 9-4 | Won 2 |
| » W: Steve Stone (3-0) L: Jim Lonborg (1-1) | First | -- |
| Friday, April 25 |
| » Defeated Cardinals (6-8), 4-3 | Wrigley Field (6-2) | 10-4 | Won 3 |
| » W: Darold Knowles (1-0) L: Al Hrabosky (0-1) | First | -- |
| Former Cub Bruce Edwards dies in Sacramento, CA at the age of 52. |
| Saturday, April 26 |
| » Defeated Cardinals (6-9), 8-6 | Wrigley Field (7-2) | 11-4 | Won 4 |
| » W: Ken Frailing (2-1) L: Jack Curtis (0-1) S: Oscar Zamora (2) | First | -- |
| Tuesday, April 29 |
| » Lost to Mets (9-6), 9-1 | Wrigley Field (7-3) | 11-5 | |
| » W: Tom Seaver (3-2) L: Burt Hooton (0-2) | First | -- |
| Wednesday, April 30 |
| » Defeated Mets (9-7), 7-4 | Wrigley Field (8-3) | 12-5 | |
| » W: Ray Burris (3-0) L: Jon Matlack (2-2) S: Oscar Zamora (3) | First | -- |
| Thursday, May 1 |
| » Defeated Mets (9-8), 5-2 | Wrigley Field (9-3) | 13-5 | Won 2 |
| » W: Steve Stone (4-0) L: Randy Tate (1-1) S: Darold Knowles (3) | First | -- |
| Friday, May 2 |
| » Lost to Cardinals (8-10), 5-1 | Busch Stadium II (0-1) | 13-6 | |
| » W: Bob Forsch (2-2) L: Rick Reuschel (1-2) | First | -- |
| Saturday, May 3 |
| » Defeated Cardinals (8-11), 7-3 | Busch Stadium II (1-1) | 14-6 | |
| » W: Bill Bonham (2-1) L: Mike Garman (1-1) S: Darold Knowles (4) | First | -- |
| Sunday, May 4 |
| » Defeated Cardinals (8-12), 8-6 | Busch Stadium II (2-1) | 15-6 | Won 2 |
| » W: Oscar Zamora (2-0) L: Lynn McGlothen (2-2) S: Darold Knowles (5) | First | -- |
| Monday, May 5 |
| » Lost to Expos (7-12), 3-2 | Parc Jarry (0-1) | 15-7 | |
| » W: Dennis Blair (1-3) L: Ray Burris (3-1) S: Chuck Taylor (1) | First | -- |
| Tuesday, May 6 |
| » Lost to Expos (8-12), 9-4 | Parc Jarry (0-2) | 15-8 | Lost 2 |
| » W: Steve Rogers (1-4) L: Rick Reuschel (1-3) S: Chuck Taylor (2) | First | -- |
| Wednesday, May 7 |
| » Defeated Expos (8-13), 7-0 | Parc Jarry (1-2) | 16-8 | |
| » W: Bill Bonham (3-1) L: Dave McNally (3-3) | First | -- |
| Friday, May 9 |
| » Defeated Padres (14-15), 5-2 | Wrigley Field (10-3) | 17-8 | Won 2 |
| » W: Ray Burris (4-1) L: Joe McIntosh (3-2) S: Darold Knowles (6) | First | -- |
| Saturday, May 10 |
| » Defeated Padres (14-16), 5-1 | Wrigley Field (11-3) | 18-8 | Won 3 |
| » W: Rick Reuschel (2-3) L: Sonny Siebert (3-2) S: Geoff Zahn (1) | First | -- |
| Sunday, May 11 |
| » Lost to Padres (15-16), 2-1 | Wrigley Field (11-4) | 18-9 | |
| » W: Dave Freisleben (2-3) L: Bill Bonham (3-2) | First | -- |
| Tuesday, May 13 |
| » Defeated Astros (11-24), 2-1 | Wrigley Field (12-4) | 19-9 | |
| » W: Steve Stone (5-0) L: Doug Konieczny (1-5) S: Oscar Zamora (4) | First | -- |
| Wednesday, May 14 |
| » Lost to Astros (12-24), 11-7 | Wrigley Field (12-5) | 19-10 | |
| » W: Tom Griffin (1-5) L: Ray Burris (4-2) S: Joe Niekro (1) | First | -- |
| Thursday, May 15 |
| » Defeated Astros (12-25), 4-2 | Wrigley Field (13-5) | 20-10 | |
| » W: Rick Reuschel (3-3) L: J.R. Richard (3-2) | First | -- |
| Friday, May 16 |
| » Lost to Padres (16-18), 8-2 | San Diego/Jack Murphy Stadium (0-1) | 20-11 | |
| » W: Joe McIntosh (4-2) L: Bill Bonham (3-3) | First | -- |
| Saturday, May 17 |
| » Lost to Padres (17-18), 4-1 | San Diego/Jack Murphy Stadium (0-2) | 20-12 | Lost 2 |
| » W: Dave Freisleben (3-3) L: Darold Knowles (1-1) | First | -- |
| Sunday, May 18 |
| » Defeated Padres (17-19), 3-2 | San Diego/Jack Murphy Stadium (1-2) | 21-12 | |
| » W: Ray Burris (5-2) L: Dan Spillner (2-5) S: Oscar Zamora (5) | First | -- |
| Monday, May 19 |
| » Lost to Dodgers (25-14), 3-2 | Dodger Stadium (0-1) | 21-13 | |
| » W: Jim Brewer (3-1) L: Darold Knowles (1-2) | First | -- |
| Tuesday, May 20 |
| » Defeated Dodgers (25-15), 2-1 | Dodger Stadium (1-1) | 22-13 | |
| » W: Bill Bonham (4-3) L: Don Sutton (7-3) | First | -- |
| Wednesday, May 21 |
| » Lost to Dodgers (26-15), 10-0 | Dodger Stadium (1-2) | 22-14 | |
| » W: Andy Messersmith (7-0) L: Geoff Zahn (0-2) | First | -- |
| Thursday, May 22 |
| » Lost to Dodgers (27-15), 8-3 | Dodger Stadium (1-3) | 22-15 | Lost 2 |
| » W: Burt Hooton (2-4) L: Ray Burris (5-3) | First | -- |
| Friday, May 23 |
| » Lost to Giants (20-19), 3-2 | Candlestick Park (0-1) | 22-16 | Lost 3 |
| » W: Pete Falcone (4-3) L: Rick Reuschel (3-4) S: Gary Lavelle (1) | First | -- |
| Saturday, May 24 |
| » Lost to Giants (21-19), 10-3 | Candlestick Park (0-2) | 22-17 | Lost 4 |
| » W: Jim Barr (6-3) L: Bill Bonham (4-4) | First | -- |
| Sunday, May 25 |
| » Lost to Giants (22-19), 9-7 | Candlestick Park (0-3) | 22-18 | Lost 5 |
| » W: Charlie Williams (1-2) L: Ken Frailing (2-2) S: Gary Lavelle (2) | First | -- |
| Monday, May 26 |
| » Defeated Braves (22-24), 6-0 | Wrigley Field (14-5) | 23-18 | |
| » W: Ray Burris (6-3) L: Roric Harrison (3-3) | First | -- |
| Tuesday, May 27 |
| » Lost to Braves (23-24), 7-2 | Wrigley Field (14-6) | 23-19 | |
| » W: Phil Niekro (5-4) L: Rick Reuschel (3-5) | First | -- |
| Wednesday, May 28 |
| » Defeated Braves (23-25), 5-4 | Wrigley Field (15-6) | 24-19 | |
| » W: Oscar Zamora (3-0) L: Carl Morton (5-5) | First | -- |
| Friday, May 30 |
| » Lost to Dodgers (30-19), 3-1 | Wrigley Field (15-7) | 24-20 | |
| » W: Don Sutton (9-3) L: Ray Burris (6-4) S: Andy Messersmith (1) | Second | 1½ out |
| Saturday, May 31 |
| » Defeated Dodgers (30-20), 2-1 | Wrigley Field (16-7) | 25-20 | |
| » W: Rick Reuschel (4-5) L: Andy Messersmith (7-2) | Second | 1½ out |
| Sunday, June 1 |
| » Defeated Dodgers (30-21), 7-2 | Wrigley Field (17-7) | 26-20 | Won 2 |
| » W: Bill Bonham (5-4) L: Burt Hooton (3-5) S: Oscar Zamora (6) | First | -- |
| Monday, June 2 |
| Future Cub Steve Rain is born in Los Angeles, CA. |
| Tuesday, June 3 |
| » Defeated Giants (24-23), 6-5 | Wrigley Field (18-7) | 27-20 | Won 3 |
| » W: Geoff Zahn (1-2) L: Randy Moffitt (3-1) | First | -- |
| Future Cub Jose Molina is born in Bayamon, P.R. |
| Wednesday, June 4 |
| » Lost to Giants (25-23), 10-8 | Wrigley Field (18-8) | 27-21 | |
| » W: Charlie Williams (2-2) L: Oscar Zamora (3-1) S: Mike Caldwell (1) | First | -- |
| Thursday, June 5 |
| » Defeated Giants (25-24), 8-4 | Wrigley Field (19-8) | 28-21 | |
| » W: Darold Knowles (2-2) L: Randy Moffitt (3-2) | First | -- |
| Friday, June 6 |
| » Lost to Reds (31-22), 5-1 | Riverfront Stadium (0-1) | 28-22 | |
| » W: Don Gullett (7-3) L: Bill Bonham (5-5) | Second | 2 out |
| Saturday, June 7 |
| » Lost to Reds (32-22), 8-1 | Riverfront Stadium (0-2) | 28-23 | Lost 2 |
| » W: Jack Billingham (6-3) L: Ray Burris (6-5) | Second | 2 out |
| Sunday, June 8 |
| » Lost to Reds (33-22), 2-1 | Riverfront Stadium (0-3) | 28-24 | Lost 3 |
| » W: Gary Nolan (6-3) L: Rick Reuschel (4-6) | Fourth | 2 out |
| » Lost to Reds (34-22), 8-5 | Riverfront Stadium (0-4) | 28-25 | Lost 4 |
| » W: Pedro Borbon (3-1) L: Geoff Zahn (1-3) S: Will McEnaney (4) | Fourth | 2 out |
| Monday, June 9 |
| » Defeated Astros (20-40), 4-3 | Astrodome (1-0) | 29-25 | |
| » W: Oscar Zamora (4-1) L: Wayne Granger (0-1) S: Darold Knowles (7) | Second | 2 out |
| Tuesday, June 10 |
| » Lost to Astros (21-40), 4-3 | Astrodome (1-1) | 29-26 | |
| » W: Doug Konieczny (4-7) L: Eddie Watt (0-1) | Fourth | 2 out |
| Thursday, June 12 |
| » Lost to Braves (27-32), 5-4 | Atlanta-Fulton County Stadium (0-1) | 29-27 | Lost 2 |
| » W: Tom House (2-2) L: Ken Frailing (2-3) | Fourth | 3 out |
| » Lost to Braves (28-32), 6-2 | Atlanta-Fulton County Stadium (0-2) | 29-28 | Lost 3 |
| » W: Carl Morton (7-6) L: Geoff Zahn (1-4) | Fourth | 3 out |
| Friday, June 13 |
| » Lost to Reds (37-24), 18-11 | Wrigley Field (19-9) | 29-29 | Lost 4 |
| » W: Pedro Borbon (4-1) L: Oscar Zamora (4-2) | Fifth | 4 out |
| Saturday, June 14 |
| » Lost to Reds (38-24), 11-3 | Wrigley Field (19-10) | 29-30 | Lost 5 |
| » W: Clay Kirby (4-3) L: Steve Stone (5-1) | Fourth | 5 out |
| Sunday, June 15 |
| » Defeated Reds (38-25), 4-3 | Wrigley Field (20-10) | 30-30 | |
| » W: Bill Bonham (6-5) L: Pat Darcy (1-4) S: Oscar Zamora (7) | Fourth | 5 out |
| Monday, June 16 |
| » Defeated Phillies (32-28), 9-7 | Wrigley Field (21-10) | 31-30 | Won 2 |
| » W: Geoff Zahn (2-4) L: Gene Garber (5-4) S: Ken Frailing (1) | Fourth | 5 out |
| Future Cub Jose Nieves is born in Guacara, Venezuela. |
| Tuesday, June 17 |
| » Defeated Phillies (32-29), 9-5 | Wrigley Field (22-10) | 32-30 | Won 3 |
| » W: Tom Dettore (1-0) L: Jim Lonborg (6-4) | Fourth | 4 out |
| Wednesday, June 18 |
| » Lost to Phillies (33-29), 9-7 | Wrigley Field (22-11) | 32-31 | |
| » W: Gene Garber (6-4) L: Bob Locker (0-1) | Fourth | 5 out |
| Future Cub Felix Heredia is born in Barahona, D.R. |
| Thursday, June 19 |
| » Lost to Phillies (34-29), 6-3 | Wrigley Field (22-12) | 32-32 | Lost 2 |
| » W: Tug McGraw (4-3) L: Darold Knowles (2-3) | Fourth | 6 out |
| Friday, June 20 |
| » Lost to Cardinals (29-32), 8-3 | Busch Stadium II (2-2) | 32-33 | Lost 3 |
| » W: Bob Forsch (7-5) L: Geoff Zahn (2-5) | Fourth | 7 out |
| Saturday, June 21 |
| » Defeated Cardinals (29-33), 6-1 | Busch Stadium II (3-2) | 33-33 | |
| » W: Rick Reuschel (5-6) L: Bob Gibson (1-6) | Fourth | 7 out |
| Sunday, June 22 |
| » Lost to Cardinals (30-33), 7-2 | Busch Stadium II (3-3) | 33-34 | |
| » W: Lynn McGlothen (8-5) L: Steve Stone (5-2) | Fourth | 8 out |
| Monday, June 23 |
| » Defeated Expos (28-35), 6-0 | Parc Jarry (2-2) | 34-34 | |
| » W: Ray Burris (7-5) L: Fred Scherman (0-2) | Fourth | 7 out |
| Former Cub Marty Callaghan dies in Norfolk, MA at the age of 76. |
| Tuesday, June 24 |
| » Defeated Expos (28-36), 13-6 | Parc Jarry (3-2) | 35-34 | Won 2 |
| » W: Bill Bonham (7-5) L: Dan Warthen (3-2) | Fourth | 5½ out |
| Wednesday, June 25 |
| » Lost to Expos (29-36), 12-6 | Parc Jarry (3-3) | 35-35 | |
| » W: Dennis Blair (5-8) L: Rick Reuschel (5-7) | Fourth | 5½ out |
| Thursday, June 26 |
| » Lost to Pirates (40-28), 5-2 | Three Rivers Stadium (1-1) | 35-36 | Lost 2 |
| » W: John Candelaria (2-1) L: Ken Frailing (2-4) | Fourth | 6½ out |
| Friday, June 27 |
| » Lost to Pirates (41-28), 5-1 | Three Rivers Stadium (1-2) | 35-37 | Lost 3 |
| » W: Dock Ellis (5-4) L: Geoff Zahn (2-6) | Fifth | 8½ out |
| » Lost to Pirates (42-28), 5-3 | Three Rivers Stadium (1-3) | 35-38 | Lost 4 |
| » W: Ramon Hernandez (4-2) L: Darold Knowles (2-4) S: Dave Giusti (7) | Fifth | 8½ out |
| Saturday, June 28 |
| » Defeated Pirates (42-29), 1-0 | Three Rivers Stadium (2-3) | 36-38 | |
| » W: Bill Bonham (8-5) L: Jim Rooker (5-4) | Fifth | 7½ out |
| Sunday, June 29 |
| » Lost to Pirates (43-29), 4-3 | Three Rivers Stadium (2-4) | 36-39 | |
| » W: Dave Giusti (3-3) L: Rick Reuschel (5-8) | Fifth | 9½ out |
| » Lost to Pirates (44-29), 7-0 | Three Rivers Stadium (2-5) | 36-40 | Lost 2 |
| » W: Jerry Reuss (9-5) L: Tom Dettore (1-1) | Fifth | 9½ out |
| Monday, June 30 |
| » Lost to Mets (37-34), 5-1 | Shea Stadium (1-3) | 36-41 | Lost 3 |
| » W: George Stone (2-1) L: Steve Stone (5-3) | Fifth | 10½ out |
| Tuesday, July 1 |
| » Defeated Mets (37-35), 5-4 | Shea Stadium (2-3) | 37-41 | |
| » W: Tom Dettore (2-1) L: Rick Baldwin (1-3) | Fifth | 10½ out |
| Wednesday, July 2 |
| » Lost to Mets (38-35), 7-2 | Shea Stadium (2-4) | 37-42 | |
| » W: Jon Matlack (10-5) L: Bill Bonham (8-6) | Fifth | 11 out |
| Thursday, July 3 |
| » Lost to Mets (39-35), 4-0 | Shea Stadium (2-5) | 37-43 | Lost 2 |
| » W: Jerry Koosman (7-6) L: Rick Reuschel (5-9) | Fifth | 12 out |
| Friday, July 4 |
| » Defeated Pirates (47-30), 6-1 | Wrigley Field (23-12) | 38-43 | |
| » W: Steve Stone (6-3) L: Bruce Kison (7-4) | Fifth | 10 out |
| » Defeated Pirates (47-31), 2-1 | Wrigley Field (24-12) | 39-43 | Won 2 |
| » W: Darold Knowles (3-4) L: Jerry Reuss (9-6) | Fifth | 10 out |
| Saturday, July 5 |
| » Lost to Pirates (48-31), 5-4 | Wrigley Field (24-13) | 39-44 | |
| » W: Jim Rooker (6-4) L: Ray Burris (7-6) S: Ramon Hernandez (3) | Fifth | 11 out |
| Sunday, July 6 |
| » Lost to Pirates (49-31), 18-12 | Wrigley Field (24-14) | 39-45 | Lost 2 |
| » W: Ramon Hernandez (5-2) L: Ken Frailing (2-5) | Fifth | 12 out |
| Monday, July 7 |
| » Lost to Pirates (50-31), 5-0 | Wrigley Field (24-15) | 39-46 | Lost 3 |
| » W: Ken Brett (5-2) L: Rick Reuschel (5-10) S: Dave Giusti (8) | Fifth | 13 out |
| Tuesday, July 8 |
| » Lost to Padres (39-45), 8-6 | Wrigley Field (24-16) | 39-47 | Lost 4 |
| » W: Joe McIntosh (7-7) L: Tom Dettore (2-2) | Fifth | 13 out |
| Wednesday, July 9 |
| » Lost to Padres (40-45), 3-2 | Wrigley Field (24-17) | 39-48 | Lost 5 |
| » W: Brent Strom (4-2) L: Geoff Zahn (2-7) S: Bill Greif (6) | Fifth | 14 out |
| Thursday, July 10 |
| » Defeated Padres (40-46), 3-1 | Wrigley Field (25-17) | 40-48 | |
| » W: Ray Burris (8-6) L: Dave Freisleben (3-9) | Fifth | 14 out |
| Friday, July 11 |
| » Defeated Giants (40-46), 8-6 | Wrigley Field (26-17) | 41-48 | Won 2 |
| » W: Tom Dettore (3-2) L: Randy Moffitt (3-3) S: Darold Knowles (8) | Fifth | 14½ out |
| Saturday, July 12 |
| » Defeated Giants (40-47), 6-4 | Wrigley Field (27-17) | 42-48 | Won 3 |
| » W: Steve Stone (7-3) L: Mike Caldwell (5-9) | Fifth | 14½ out |
| Sunday, July 13 |
| » Lost to Giants (41-47), 4-1 | Wrigley Field (27-18) | 42-49 | |
| » W: John Montefusco (7-4) L: Geoff Zahn (2-8) S: Charlie Williams (1) | Fifth | 14½ out |
| Thursday, July 17 |
| » Defeated Padres (41-50), 6-5 | San Diego/Jack Murphy Stadium (2-2) | 43-49 | |
| » W: Rick Reuschel (6-10) L: Brent Strom (5-3) S: Darold Knowles (9) | Fifth | 14½ out |
| Friday, July 18 |
| » Lost to Padres (42-50), 4-2 | San Diego/Jack Murphy Stadium (2-3) | 43-50 | |
| » W: Bill Greif (2-2) L: Milt Wilcox (0-1) S: Danny Frisella (5) | Fifth | 14½ out |
| Saturday, July 19 |
| » Lost to Padres (43-50), 2-1 | San Diego/Jack Murphy Stadium (2-4) | 43-51 | Lost 2 |
| » W: Dave Freisleben (4-9) L: Steve Stone (7-4) | Fifth | 15½ out |
| Sunday, July 20 |
| » Lost to Dodgers (51-44), 5-3 | Dodger Stadium (1-4) | 43-52 | Lost 3 |
| » W: Mike Marshall (6-7) L: Tom Dettore (3-3) | Fifth | 16 out |
| Monday, July 21 |
| » Defeated Dodgers (51-45), 1-0 | Dodger Stadium (2-4) | 44-52 | |
| » W: Rick Reuschel (7-10) L: Andy Messersmith (12-8) S: Oscar Zamora (8) | Fifth | 15 out |
| Tuesday, July 22 |
| » Lost to Giants (46-49), 9-5 | Candlestick Park (0-4) | 44-53 | |
| » W: Charlie Williams (4-2) L: Ray Burris (8-7) S: Randy Moffitt (8) | Fifth | 15 out |
| Wednesday, July 23 |
| » Lost to Giants (47-49), 10-2 | Candlestick Park (0-5) | 44-54 | Lost 2 |
| » W: John Montefusco (9-4) L: Steve Stone (7-5) | Fifth | 16 out |
| Thursday, July 24 |
| » Defeated Giants (47-50), 4-3 | Candlestick Park (1-5) | 45-54 | |
| » W: Bill Bonham (9-6) L: Ed Halicki (4-7) S: Oscar Zamora (9) | Fifth | 15½ out |
| Friday, July 25 |
| » Lost to Mets (49-45), 6-3 | Wrigley Field (27-19) | 45-55 | |
| » W: Randy Tate (4-8) L: Rick Reuschel (7-11) S: Ken Sanders (2) | Fifth | 16½ out |
| » Major-league debuts: Paul Reuschel (Cubs) |
| Saturday, July 26 |
| » Lost to Mets (50-45), 9-8 | Wrigley Field (27-20) | 45-56 | Lost 2 |
| » W: Tom Hall (3-2) L: Darold Knowles (3-5) S: Rick Baldwin (5) | Fifth | 16½ out |
| Sunday, July 27 |
| » Defeated Mets (50-46), 4-2 | Wrigley Field (28-20) | 46-56 | |
| » W: Steve Stone (8-5) L: Jerry Koosman (9-8) | Fifth | 17½ out |
| » Lost to Mets (51-46), 4-1 | Wrigley Field (28-21) | 46-57 | |
| » W: Hank Webb (3-3) L: Paul Reuschel (0-1) S: Ken Sanders (3) | Fifth | 17½ out |
| Monday, July 28 |
| » Defeated Expos (40-57), 4-2 | Wrigley Field (29-21) | 47-57 | |
| » W: Bill Bonham (10-6) L: Dennis Blair (6-12) | Fifth | 16½ out |
| Tuesday, July 29 |
| » Defeated Expos (40-58), 4-3 | Wrigley Field (30-21) | 48-57 | Won 2 |
| » W: Darold Knowles (4-5) L: Dale Murray (4-4) S: Oscar Zamora (10) | Fifth | 15½ out |
| Wednesday, July 30 |
| » Lost to Expos (41-58), 6-1 | Wrigley Field (30-22) | 48-58 | |
| » W: Steve Rogers (8-7) L: Ray Burris (8-8) | Fifth | 16½ out |
| Future Cub Oswaldo Mairena is born in Chinandega, Nicaragua. |
| Thursday, July 31 |
| » Defeated Cardinals (52-52), 5-3 | Wrigley Field (31-22) | 49-58 | |
| » W: Paul Reuschel (1-1) L: Ken Reynolds (0-1) | Fifth | 15½ out |
| Friday, August 1 |
| » Lost to Cardinals (53-52), 9-4 | Wrigley Field (31-23) | 49-59 | |
| » W: John Denny (5-3) L: Bill Bonham (10-7) S: Bob Gibson (1) | Fifth | 15½ out |
| Saturday, August 2 |
| » Lost to Cardinals (54-52), 4-0 | Wrigley Field (31-24) | 49-60 | Lost 2 |
| » W: Bob Forsch (10-8) L: Rick Reuschel (7-12) | Fifth | 15½ out |
| Sunday, August 3 |
| » Defeated Cardinals (54-53), 6-3 | Wrigley Field (32-24) | 50-60 | |
| » W: Tom Dettore (4-3) L: Al Hrabosky (9-3) S: Darold Knowles (10) | Fifth | 16½ out |
| » Lost to Cardinals (55-53), 7-4 | Wrigley Field (32-25) | 50-61 | |
| » W: Ron Reed (10-9) L: Ray Burris (8-9) | Fifth | 16½ out |
| Future Cub Roosevelt Brown is born in Vicksburg, MS. |
| Monday, August 4 |
| » Defeated Phillies (61-49), 3-2 | Veteran's Stadium (3-0) | 51-61 | |
| » W: Steve Stone (9-5) L: Tom Hilgendorf (2-3) S: Paul Reuschel (1) | Fifth | 15½ out |
| Tuesday, August 5 |
| » Lost to Phillies (62-49), 13-5 | Veteran's Stadium (3-1) | 51-62 | |
| » W: Dick Ruthven (1-0) L: Bill Bonham (10-8) | Fifth | 16½ out |
| Thursday, August 7 |
| » Defeated Phillies (62-50), 5-3 | Veteran's Stadium (4-1) | 52-62 | |
| » W: Rick Reuschel (8-12) L: Larry Christenson (6-3) | Fifth | 15 out |
| Friday, August 8 |
| » Lost to Braves (51-62), 1-0 | Atlanta-Fulton County Stadium (0-3) | 52-63 | |
| » W: Carl Morton (14-12) L: Tom Dettore (4-4) | Fourth | 14½ out |
| » Defeated Braves (51-63), 3-1 | Atlanta-Fulton County Stadium (1-3) | 53-63 | |
| » W: Ray Burris (9-9) L: Bruce Dal Canton (0-7) S: Darold Knowles (11) | Fourth | 14½ out |
| Future Cub Chad Meyers is born in Omaha, NE. |
| Saturday, August 9 |
| » Defeated Braves (51-64), 8-2 | Atlanta-Fulton County Stadium (2-3) | 54-63 | Won 2 |
| » W: Steve Stone (10-5) L: Phil Niekro (11-10) | Fifth | 13½ out |
| Sunday, August 10 |
| » Defeated Braves (51-65), 9-1 | Atlanta-Fulton County Stadium (3-3) | 55-63 | Won 3 |
| » W: Bill Bonham (11-8) L: Blue Moon Odom (2-7) | Fifth | 12½ out |
| Monday, August 11 |
| » Lost to Reds (77-39), 9-3 | Riverfront Stadium (0-5) | 55-64 | |
| » W: Jack Billingham (13-5) L: Rick Reuschel (8-13) | Fifth | 13½ out |
| Tuesday, August 12 |
| » Lost to Reds (78-39), 12-8 | Riverfront Stadium (0-6) | 55-65 | Lost 2 |
| » W: Rawly Eastwick (2-2) L: Darold Knowles (4-6) | Fifth | 13½ out |
| Thursday, August 14 |
| » Defeated Astros (45-78), 5-3 | Astrodome (2-1) | 56-65 | |
| » W: Steve Stone (11-5) L: J.R. Richard (8-8) | Fifth | 12 out |
| Friday, August 15 |
| » Lost to Astros (46-78), 4-1 | Astrodome (2-2) | 56-66 | |
| » W: Larry Dierker (11-12) L: Bill Bonham (11-9) | Fifth | 12 out |
| Saturday, August 16 |
| » Defeated Astros (46-79), 3-2 | Astrodome (3-2) | 57-66 | |
| » W: Rick Reuschel (9-13) L: Dave Roberts (7-14) | Fifth | 11 out |
| Sunday, August 17 |
| » Defeated Astros (46-80), 11-7 | Astrodome (4-2) | 58-66 | Won 2 |
| » W: Ray Burris (10-9) L: Jim Crawford (2-4) | Fifth | 10 out |
| Monday, August 18 |
| » Lost to Dodgers (66-57), 3-1 | Wrigley Field (32-26) | 58-67 | |
| » W: Burt Hooton (11-9) L: Steve Stone (11-6) S: Mike Marshall (12) | Fourth | 10½ out |
| Tuesday, August 19 |
| » Lost to Dodgers (67-57), 2-1 | Wrigley Field (32-27) | 58-68 | Lost 2 |
| » W: Mike Marshall (9-12) L: Bill Bonham (11-10) | Fifth | 11½ out |
| Thursday, August 21 |
| » Defeated Dodgers (67-58), 7-0 | Wrigley Field (33-27) | 59-68 | |
| » W: Rick Reuschel (10-13) L: Andy Messersmith (14-12) | Fifth | 11½ out |
| Friday, August 22 |
| » Defeated Astros (48-82), 6-5 | Wrigley Field (34-27) | 60-68 | Won 2 |
| » W: Darold Knowles (5-6) L: Jim Crawford (3-5) | Fifth | 12 out |
| Saturday, August 23 |
| » Lost to Astros (49-82), 14-12 | Wrigley Field (34-28) | 60-69 | |
| » W: Jim York (1-2) L: Bill Bonham (11-11) S: Mike Cosgrove (5) | Fifth | 12 out |
| Sunday, August 24 |
| » Lost to Astros (50-82), 8-4 | Wrigley Field (34-29) | 60-70 | Lost 2 |
| » W: Larry Dierker (12-13) L: Ray Burris (10-10) | Fourth | 13 out |
| Monday, August 25 |
| » Lost to Reds (85-44), 11-4 | Wrigley Field (34-30) | 60-71 | Lost 3 |
| » W: Fred Norman (9-4) L: Rick Reuschel (10-14) S: Clay Carroll (7) | Fifth | 14 out |
| Tuesday, August 26 |
| » Lost to Reds (86-44), 6-5 | Wrigley Field (34-31) | 60-72 | Lost 4 |
| » W: Rawly Eastwick (3-2) L: Steve Stone (11-7) S: Will McEnaney (12) | Fifth | 15 out |
| Wednesday, August 27 |
| » Lost to Reds (87-44), 6-5 | Wrigley Field (34-32) | 60-73 | Lost 5 |
| » W: Pedro Borbon (8-4) L: Bill Bonham (11-12) S: Rawly Eastwick (17) | Fifth | 15 out |
| Friday, August 29 |
| » Defeated Braves (58-76), 8-3 | Wrigley Field (35-32) | 61-73 | |
| » W: Ray Burris (11-10) L: Carl Morton (15-15) | Fourth | 14½ out |
| Sunday, August 31 |
| » Lost to Braves (59-76), 3-1 | Wrigley Field (35-33) | 61-74 | |
| » W: Phil Niekro (14-12) L: Rick Reuschel (10-15) | Fourth | 14½ out |
| » Defeated Braves (59-77), 9-8 | Wrigley Field (36-33) | 62-74 | |
| » W: Tom Dettore (5-4) L: Ray Sadecki (3-3) | Fourth | 14½ out |
| Monday, September 1 |
| » Lost to Cardinals (73-63), 6-3 | Busch Stadium II (3-4) | 62-75 | |
| » W: Bob Forsch (13-9) L: Bill Bonham (11-13) S: Al Hrabosky (20) | Fourth | 14½ out |
| Tuesday, September 2 |
| » Defeated Cardinals (73-64), 5-3 | Busch Stadium II (4-4) | 63-75 | |
| » W: Ray Burris (12-10) L: Lynn McGlothen (13-11) S: Paul Reuschel (2) | Fourth | 14½ out |
| » Major-league debuts: Joe Wallis (Cubs) |
| Wednesday, September 3 |
| » Defeated Cardinals (73-65), 11-6 | Busch Stadium II (5-4) | 64-75 | Won 2 |
| » W: Buddy Schultz (1-0) L: Bob Gibson (3-10) S: Paul Reuschel (3) | Fourth | 14½ out |
| » Major-league debuts: Buddy Schultz (Cubs) |
| Friday, September 5 |
| » Defeated Phillies (73-66), 4-3 | Veteran's Stadium (5-1) | 65-75 | Won 3 |
| » W: Bill Bonham (12-13) L: Steve Carlton (11-13) S: Paul Reuschel (4) | Fourth | 14½ out |
| » Lost to Phillies (74-66), 6-3 | Veteran's Stadium (5-2) | 65-76 | |
| » W: Tug McGraw (8-5) L: Paul Reuschel (1-2) | Fourth | 14½ out |
| Saturday, September 6 |
| » Defeated Phillies (74-67), 7-6 | Veteran's Stadium (6-2) | 66-76 | |
| » W: Steve Stone (12-7) L: Gene Garber (9-10) S: Darold Knowles (12) | Fifth | 14½ out |
| Sunday, September 7 |
| » Defeated Phillies (74-68), 6-4 | Veteran's Stadium (7-2) | 67-76 | Won 2 |
| » W: Ray Burris (13-10) L: Wayne Twitchell (5-10) S: Rick Reuschel (1) | Fifth | 14½ out |
| Monday, September 8 |
| » Lost to Pirates (81-60), 4-1 | Three Rivers Stadium (2-6) | 67-77 | |
| » W: Dock Ellis (8-7) L: Willie Prall (0-1) S: Ramon Hernandez (5) | Fifth | 15½ out |
| Tuesday, September 9 |
| » Defeated Pirates (81-61), 6-5 | Three Rivers Stadium (3-6) | 68-77 | |
| » W: Bill Bonham (13-13) L: Larry Demery (7-4) S: Paul Reuschel (5) | Fifth | 14½ out |
| Wednesday, September 10 |
| » Defeated Cardinals (75-69), 7-5 | Wrigley Field (37-33) | 69-77 | Won 2 |
| » W: Buddy Schultz (2-0) L: Eric Rasmussen (4-4) S: Darold Knowles (13) | Fifth | 14½ out |
| Former Cub Lance Richbourg dies in Crestview, FL at the age of 78. |
| Thursday, September 11 |
| » Defeated Cardinals (75-70), 12-6 | Wrigley Field (38-33) | 70-77 | Won 3 |
| » W: Oscar Zamora (5-2) L: Bob Forsch (14-10) S: Darold Knowles (14) | Fifth | 13½ out |
| Saturday, September 13 |
| » Defeated Phillies (78-69), 4-1 | Wrigley Field (39-33) | 71-77 | Won 4 |
| » W: Ray Burris (14-10) L: Tom Underwood (14-11) | Fifth | 13 out |
| Sunday, September 14 |
| » Lost to Phillies (79-69), 13-7 | Wrigley Field (39-34) | 71-78 | |
| » W: Steve Carlton (13-13) L: Steve Stone (12-8) | Fifth | 14 out |
| » Major-league debuts: Donnie Moore (Cubs) Randy Lerch (Phillies) |
| Monday, September 15 |
| » Defeated Pirates |
