| Thursday, January 7 |
| Former Pirate Hal Rhyne dies in Orangevale, CA at the age of 72. |
| Wednesday, January 13 |
| Future Pirate Elmer Dessens is born in Hermosillo, Mexico. |
| Thursday, January 21 |
| Future Pirate Brian Giles is born in ElCajon, CA. |
| Thursday, February 4 |
| Future Pirate Dennis Konuszewski is born in Bridgeport, MI. |
| Friday, February 19 |
| Future Pirate Miguel Batista is born in Santo Domingo, D.R. |
| Tuesday, March 2 |
| Former Pirate Johnny Podgajny dies in Chester, PA at the age of 51. |
| Friday, March 12 |
| Future Pirate Greg Hansell is born in Bellflower, CA. |
| Tuesday, March 16 |
| Former Pirate Ralph Birkofer dies in Cincinnati, OH at the age of 63. |
| Monday, March 29 |
| Future Pirate Sean Lowe is born in Dallas, TX. |
| Tuesday, April 6 |
| » Defeated Phillies (0-1), 4-2 | Three Rivers Stadium (1-0) | 1-0 | |
| » Starters: Chris Short vs Dock Ellis | First | -- |
| Wednesday, April 7 |
| » Major-league debuts: Bill Bonham and Hal Breeden (Cubs) |
| Thursday, April 8 |
| » Defeated Phillies (0-2), 2-0 | Three Rivers Stadium (2-0) | 2-0 | Won 2 |
| » Starters: Woodie Fryman vs Luke Walker | First | -- |
| Friday, April 9 |
| » Defeated Braves (2-1), 8-2 | Atlanta-Fulton County Stadium (1-0) | 3-0 | Won 3 |
| » Starters: Bob Moose vs Pat Jarvis | First | -- |
| Saturday, April 10 |
| » Lost to Braves (3-1), 5-4 | Atlanta-Fulton County Stadium (1-1) | 3-1 | |
| » Starters: Steve Blass vs Phil Niekro | First | -- |
| Sunday, April 11 |
| » Lost to Braves (4-1), 3-1 | Atlanta-Fulton County Stadium (1-2) | 3-2 | Lost 2 |
| » Starters: Dock Ellis vs Jim Nash | Second | ½ out |
| Monday, April 12 |
| » Defeated Phillies (2-3), 4-3 | Veteran's Stadium (1-0) | 4-2 | |
| » Starters: Bob Johnson vs Rick Wise | Second | 1 out |
| Tuesday, April 13 |
| » Defeated Phillies (2-4), 9-3 | Veteran's Stadium (2-0) | 5-2 | Won 2 |
| » Starters: Luke Walker vs Chris Short | First | -- |
| Wednesday, April 14 |
| » Lost to Phillies (3-4), 6-5 | Veteran's Stadium (2-1) | 5-3 | |
| » Starters: Bob Moose vs Woodie Fryman | First | -- |
| Friday, April 16 |
| » Lost to Mets (4-2), 1-0 | Shea Stadium (0-1) | 5-4 | Lost 2 |
| » Starters: Dock Ellis vs Tom Seaver | Second | 1½ out |
| Saturday, April 17 |
| » Defeated Mets (4-3), 2-0 | Shea Stadium (1-1) | 6-4 | |
| » Starters: Steve Blass vs Jerry Koosman | First | -- |
| Sunday, April 18 |
| » Lost to Mets (5-3), 5-2 | Shea Stadium (1-2) | 6-5 | |
| » Starters: Luke Walker vs Gary Gentry | Second | 2 out |
| » Defeated Mets (5-4), 2-1 | Shea Stadium (2-2) | 7-5 | |
| » Starters: Bob Johnson vs Jim McAndrew | Second | 2 out |
| Tuesday, April 20 |
| » Lost to Braves (8-4), 2-0 | Three Rivers Stadium (2-1) | 7-6 | |
| » Starters: Phil Niekro vs Bob Moose | Third | ½ out |
| Wednesday, April 21 |
| » Defeated Braves (8-5), 10-2 | Three Rivers Stadium (3-1) | 8-6 | |
| » Starters: Jim Nash vs Dock Ellis | Second | ½ out |
| Thursday, April 22 |
| » Defeated Braves (8-6), 7-4 | Three Rivers Stadium (4-1) | 9-6 | Won 2 |
| » Starters: Ron Reed vs Steve Blass | Second | ½ out |
| Friday, April 23 |
| » Lost to Giants (13-4), 2-0 | Three Rivers Stadium (4-2) | 9-7 | |
| » Starters: Steve Stone vs Luke Walker | Fourth | 3 out |
| Saturday, April 24 |
| » Lost to Giants (14-4), 2-0 | Three Rivers Stadium (4-3) | 9-8 | Lost 2 |
| » Starters: Ron Bryant vs Bob Johnson | Fourth | 3 out |
| Sunday, April 25 |
| » Defeated Giants (14-5), 6-2 | Three Rivers Stadium (5-3) | 10-8 | |
| » Starters: Juan Marichal vs Nelson Briles | Third | 3 out |
| Future Pirate Brad Clontz is born in Stuart, VA. |
| Tuesday, April 27 |
| » Lost to Dodgers (12-9), 7-5 | Three Rivers Stadium (5-4) | 10-9 | |
| » Starters: Claude Osteen vs Dock Ellis | Fourth | 3½ out |
| Wednesday, April 28 |
| » Defeated Dodgers (12-10), 7-5 | Three Rivers Stadium (6-4) | 11-9 | |
| » Starters: Don Sutton vs Steve Blass | Third | 3½ out |
| Thursday, April 29 |
| » Lost to Dodgers (13-10), 2-1 | Three Rivers Stadium (6-5) | 11-10 | |
| » Starters: Al Downing vs Luke Walker | Third | 3½ out |
| Friday, April 30 |
| » Defeated Padres (5-16), 5-3 | Three Rivers Stadium (7-5) | 12-10 | |
| » Starters: Dave Roberts vs Bob Johnson | Third | 1½ out |
| Saturday, May 1 |
| » Defeated Padres (5-17), 5-4 | Three Rivers Stadium (8-5) | 13-10 | Won 2 |
| » Starters: Clay Kirby vs Bob Moose | Third | 1½ out |
| Sunday, May 2 |
| » Defeated Padres (5-18), 5-1 | Three Rivers Stadium (9-5) | 14-10 | Won 3 |
| » Starters: Steve Arlin vs Dock Ellis | Second | 1½ out |
| Tuesday, May 4 |
| » Defeated Giants (19-7), 10-2 | Candlestick Park (1-0) | 15-10 | Won 4 |
| » Starters: Steve Blass vs Steve Stone | Second | 1 out |
| Wednesday, May 5 |
| » Lost to Giants (20-7), 2-1 | Candlestick Park (1-1) | 15-11 | |
| » Starters: Luke Walker vs Juan Marichal | Third | 1 out |
| Friday, May 7 |
| » Defeated Dodgers (15-15), 3-2 | Dodger Stadium (1-0) | 16-11 | |
| » Starters: Bob Johnson vs Don Sutton | Second | 1 out |
| Saturday, May 8 |
| » Defeated Dodgers (15-16), 5-3 | Dodger Stadium (2-0) | 17-11 | Won 2 |
| » Starters: Nelson Briles vs Al Downing | Second | 1½ out |
| Sunday, May 9 |
| » Defeated Dodgers (15-17), 11-5 | Dodger Stadium (3-0) | 18-11 | Won 3 |
| » Starters: Steve Blass vs Sandy Vance | Second | 1½ out |
| Tuesday, May 11 |
| » Defeated Padres (9-21), 10-4 | San Diego/Jack Murphy Stadium (1-0) | 19-11 | Won 4 |
| » Starters: Dock Ellis vs Danny Coombs | Second | 1 out |
| Wednesday, May 12 |
| » Lost to Padres (10-21), 2-1 | San Diego/Jack Murphy Stadium (1-1) | 19-12 | |
| » Starters: Luke Walker vs Dave Roberts | Second | 1 out |
| Former Pirate Heinie Manush dies in Sarasota, FL at the age of 70. |
| Friday, May 14 |
| » Lost to Mets (20-10), 8-2 | Three Rivers Stadium (9-6) | 19-13 | Lost 2 |
| » Starters: Jerry Koosman vs Bob Johnson | Second | 2 out |
| Saturday, May 15 |
| » Lost to Mets (21-10), 9-5 | Three Rivers Stadium (9-7) | 19-14 | Lost 3 |
| » Starters: Gary Gentry vs Steve Blass | Third | 3 out |
| Sunday, May 16 |
| » Defeated Mets (21-11), 4-2 | Three Rivers Stadium (10-7) | 20-14 | |
| » Starters: Nolan Ryan vs Dock Ellis | Second | 2 out |
| Monday, May 17 |
| » Defeated Expos (13-14), 6-5 | Three Rivers Stadium (11-7) | 21-14 | Won 2 |
| » Starters: Carl Morton vs Luke Walker | Second | 1 out |
| Tuesday, May 18 |
| » Defeated Expos (13-15), 3-2 | Three Rivers Stadium (12-7) | 22-14 | Won 3 |
| » Starters: Bill Stoneman vs Bob Johnson | Second | 1 out |
| Wednesday, May 19 |
| » Defeated Reds (14-23), 6-1 | Riverfront Stadium (1-0) | 23-14 | Won 4 |
| » Starters: Bob Moose vs Gary Nolan | First | -- |
| Thursday, May 20 |
| » Lost to Reds (15-23), 5-4 | Riverfront Stadium (1-1) | 23-15 | |
| » Starters: Steve Blass vs Ross Grimsley | First | -- |
| Friday, May 21 |
| » Defeated Expos (14-17), 6-2 | Parc Jarry (1-0) | 24-15 | |
| » Starters: Dock Ellis vs Carl Morton | First | -- |
| Saturday, May 22 |
| » Lost to Expos (15-17), 5-2 | Parc Jarry (1-1) | 24-16 | |
| » Starters: Luke Walker vs Bill Stoneman | Second | 1 out |
| Sunday, May 23 |
| » Lost to Expos (16-17), 4-2 | Parc Jarry (1-2) | 24-17 | Lost 2 |
| » Starters: Bob Johnson vs Ernie McAnally | Third | 1 out |
| Tuesday, May 25 |
| » Lost to Reds (18-25), 7-4 | Three Rivers Stadium (12-8) | 24-18 | Lost 3 |
| » Starters: Ross Grimsley vs Bob Moose | Third | 2 out |
| Wednesday, May 26 |
| » Defeated Reds (18-26), 2-0 | Three Rivers Stadium (13-8) | 25-18 | |
| » Starters: Tony Cloninger vs Steve Blass | Third | 1½ out |
| Thursday, May 27 |
| » Defeated Reds (18-27), 5-2 | Three Rivers Stadium (14-8) | 26-18 | Won 2 |
| » Starters: Jim Merritt vs Dock Ellis | Third | 1½ out |
| Friday, May 28 |
| » Lost to Cubs (22-24), 4-2 | Three Rivers Stadium (14-9) | 26-19 | |
| » Starters: Milt Pappas vs Luke Walker | Third | 2½ out |
| Saturday, May 29 |
| » Defeated Cubs (22-25), 9-4 | Three Rivers Stadium (15-9) | 27-19 | |
| » Starters: Bill Hands vs Bob Johnson | Third | 2½ out |
| Sunday, May 30 |
| » Defeated Cubs (22-26), 10-0 | Three Rivers Stadium (16-9) | 28-19 | Won 2 |
| » Starters: Ken Holtzman vs Bob Moose | Third | 2½ out |
| Monday, May 31 |
| » Defeated Cubs (22-27), 6-0 | Three Rivers Stadium (17-9) | 29-19 | Won 3 |
| » Starters: Fergie Jenkins vs Steve Blass | Second | 2½ out |
| Tuesday, June 1 |
| » Defeated Cardinals (32-18), 9-0 | Three Rivers Stadium (18-9) | 30-19 | Won 4 |
| » Starters: Chris Zachary vs Dock Ellis | Second | 1½ out |
| Wednesday, June 2 |
| » Defeated Cardinals (32-19), 10-1 | Three Rivers Stadium (19-9) | 31-19 | Won 5 |
| » Starters: Reggie Cleveland vs Luke Walker | Second | ½ out |
| Thursday, June 3 |
| » Lost to Cardinals (33-19), 7-1 | Three Rivers Stadium (19-10) | 31-20 | |
| » Starters: Steve Carlton vs Bob Johnson | Third | 1½ out |
| Friday, June 4 |
| » Defeated Astros (26-27), 3-2 | Three Rivers Stadium (20-10) | 32-20 | |
| » Starters: Jack Billingham vs Bob Moose | Third | 2 out |
| Saturday, June 5 |
| » Lost to Astros (27-27), 4-1 | Three Rivers Stadium (20-11) | 32-21 | |
| » Starters: Larry Dierker vs Steve Blass | Third | 1½ out |
| Sunday, June 6 |
| » Defeated Astros (27-28), 9-8 | Three Rivers Stadium (21-11) | 33-21 | |
| » Starters: Wade Blasingame vs Dock Ellis | Second | ½ out |
| Monday, June 7 |
| » Defeated Cubs (27-29), 11-6 | Wrigley Field (1-0) | 34-21 | Won 2 |
| » Starters: Nelson Briles vs Milt Pappas | Second | ½ out |
| Tuesday, June 8 |
| » Lost to Cubs (28-29), 1-0 | Wrigley Field (1-1) | 34-22 | |
| » Starters: Jim Nelson vs Ken Holtzman | Third | ½ out |
| Wednesday, June 9 |
| » Lost to Cubs (29-29), 3-1 | Wrigley Field (1-2) | 34-23 | Lost 2 |
| » Starters: Bob Moose vs Fergie Jenkins | Third | 2½ out |
| Thursday, June 10 |
| » Defeated Cardinals (35-24), 3-1 | Busch Stadium II (1-0) | 35-23 | |
| » Starters: Steve Blass vs Jerry Reuss | Second | 2½ out |
| Friday, June 11 |
| » Defeated Cardinals (35-25), 11-4 | Busch Stadium II (2-0) | 36-23 | Won 2 |
| » Starters: Dock Ellis vs Reggie Cleveland | First | -- |
| Saturday, June 12 |
| » Defeated Cardinals (35-26), 4-3 | Busch Stadium II (3-0) | 37-23 | Won 3 |
| » Starters: Nelson Briles vs Mike Torrez | First | -- |
| Sunday, June 13 |
| » Defeated Cardinals (35-27), 8-4 | Busch Stadium II (4-0) | 38-23 | Won 4 |
| » Starters: Luke Walker vs Steve Carlton | First | -- |
| Monday, June 14 |
| » Lost to Astros (31-31), 5-4 | Astrodome (0-1) | 38-24 | |
| » Starters: Bob Moose vs Jack Billingham | First | -- |
| Tuesday, June 15 |
| » Defeated Astros (31-32), 3-0 | Astrodome (1-1) | 39-24 | |
| » Starters: Steve Blass vs Larry Dierker | First | -- |
| Wednesday, June 16 |
| » Defeated Astros (31-33), 6-4 | Astrodome (2-1) | 40-24 | Won 2 |
| » Starters: Dock Ellis vs Wade Blasingame | First | -- |
| Thursday, June 17 |
| » Major-league debuts: Burt Hooton (Cubs) |
| Friday, June 18 |
| » Defeated Expos (25-33), 9-8 | Three Rivers Stadium (22-11) | 41-24 | Won 3 |
| » Starters: Steve Renko vs Luke Walker | First | -- |
| Saturday, June 19 |
| » Lost to Expos (26-33), 10-1 | Three Rivers Stadium (22-12) | 41-25 | |
| » Starters: Carl Morton vs Bob Moose | First | -- |
| Sunday, June 20 |
| » Defeated Expos (26-34), 7-1 | Three Rivers Stadium (23-12) | 42-25 | |
| » Starters: Bill Stoneman vs Steve Blass | First | -- |
| » Defeated Expos (26-35), 7-3 | Three Rivers Stadium (24-12) | 43-25 | Won 2 |
| » Starters: Jim Britton vs Nelson Briles | First | -- |
| Monday, June 21 |
| » Defeated Mets (37-27), 6-0 | Three Rivers Stadium (25-12) | 44-25 | Won 3 |
| » Starters: Jerry Koosman vs Dock Ellis | First | -- |
| Tuesday, June 22 |
| » Lost to Mets (38-27), 3-2 | Three Rivers Stadium (25-13) | 44-26 | |
| » Starters: Charlie Williams vs Jim Nelson | First | -- |
| Future Pirate Brant Brown is born in Porterville, CA. |
| Wednesday, June 23 |
| » Defeated Mets (38-28), 6-2 | Three Rivers Stadium (26-13) | 45-26 | |
| » Starters: Gary Gentry vs Luke Walker | First | -- |
| Friday, June 25 |
| » Defeated Phillies (29-41), 14-4 | Veteran's Stadium (3-1) | 46-26 | Won 2 |
| » Starters: Steve Blass vs Jim Bunning | First | -- |
| Saturday, June 26 |
| » Defeated Phillies (29-42), 11-9 | Veteran's Stadium (4-1) | 47-26 | Won 3 |
| » Starters: Dock Ellis vs Chris Short | First | -- |
| Sunday, June 27 |
| » Lost to Phillies (30-42), 8-4 | Veteran's Stadium (4-2) | 47-27 | |
| » Starters: Bob Johnson vs Woodie Fryman | First | -- |
| » Defeated Phillies (30-43), 10-9 | Veteran's Stadium (5-2) | 48-27 | |
| » Starters: Nelson Briles vs Ken Reynolds | First | -- |
| Monday, June 28 |
| » Defeated Cardinals (39-38), 11-5 | Busch Stadium II (5-0) | 49-27 | Won 2 |
| » Starters: Bob Moose vs Jerry Reuss | First | -- |
| Tuesday, June 29 |
| » Lost to Cardinals (40-38), 8-3 | Busch Stadium II (5-1) | 49-28 | |
| » Starters: Luke Walker vs Reggie Cleveland | First | -- |
| Wednesday, June 30 |
| » Lost to Mets (45-29), 4-0 | Shea Stadium (2-3) | 49-29 | Lost 2 |
| » Starters: Steve Blass vs Nolan Ryan | First | -- |
| Thursday, July 1 |
| » Defeated Mets (45-30), 3-0 | Shea Stadium (3-3) | 50-29 | |
| » Starters: Dock Ellis vs Jerry Koosman | First | -- |
| Friday, July 2 |
| » Defeated Cubs (40-37), 5-1 | Wrigley Field (2-2) | 51-29 | Won 2 |
| » Starters: Bob Moose vs Fergie Jenkins | First | -- |
| Saturday, July 3 |
| » Lost to Cubs (41-37), 3-1 | Wrigley Field (2-3) | 51-30 | |
| » Starters: Bob Johnson vs Milt Pappas | First | -- |
| Sunday, July 4 |
| » Lost to Cubs (42-37), 9-7 | Wrigley Field (2-4) | 51-31 | Lost 2 |
| » Starters: Bruce Kison vs Bill Hands | First | -- |
| » Major-league debuts: Bruce Kison (Pirates) |
| Monday, July 5 |
| » Defeated Cubs (42-38), 6-2 | Wrigley Field (3-4) | 52-31 | |
| » Starters: Steve Blass vs Ken Holtzman | First | -- |
| Tuesday, July 6 |
| » Defeated Reds (37-49), 5-2 | Three Rivers Stadium (27-13) | 53-31 | Won 2 |
| » Starters: Jim McGlothlin vs Dock Ellis | First | -- |
| Wednesday, July 7 |
| » Defeated Reds (37-50), 9-3 | Three Rivers Stadium (28-13) | 54-31 | Won 3 |
| » Starters: Gary Nolan vs Bob Johnson | First | -- |
| Thursday, July 8 |
| » Defeated Reds (37-51), 7-1 | Three Rivers Stadium (29-13) | 55-31 | Won 4 |
| » Starters: Don Gullett vs Bruce Kison | First | -- |
| Friday, July 9 |
| » Defeated Braves (44-47), 11-2 | Three Rivers Stadium (30-13) | 56-31 | Won 5 |
| » Starters: Jim Nash vs Nelson Briles | First | -- |
| » Major-league debuts: Leo Foster (Braves) |
| Saturday, July 10 |
| » Defeated Braves (44-48), 5-4 | Three Rivers Stadium (31-13) | 57-31 | Won 6 |
| » Starters: Phil Niekro vs Steve Blass | First | -- |
| » Major-league debuts: Rennie Stennett (Pirates) |
| Monday, July 12 |
| Former Pirate Walt Judnich dies in Glendale, CA at the age of 55. |
| Tuesday, July 13 |
| Future Pirate Rich Aude is born in Van Nuys, CA. |
| Thursday, July 15 |
| » Defeated Padres (33-59), 4-3 | Three Rivers Stadium (32-13) | 58-31 | Won 7 |
| » Starters: Dave Roberts vs Steve Blass | First | -- |
| Friday, July 16 |
| » Defeated Padres (33-60), 2-1 | Three Rivers Stadium (33-13) | 59-31 | Won 8 |
| » Starters: Steve Arlin vs Bob Johnson | First | -- |
| Saturday, July 17 |
| » Defeated Padres (33-61), 9-2 | Three Rivers Stadium (34-13) | 60-31 | Won 9 |
| » Starters: Fred Norman vs Dock Ellis | First | -- |
| Sunday, July 18 |
| » Defeated Dodgers (50-44), 3-2 | Three Rivers Stadium (35-13) | 61-31 | Won 10 |
| » Starters: Al Downing vs Bruce Kison | First | -- |
| » Defeated Dodgers (50-45), 7-1 | Three Rivers Stadium (36-13) | 62-31 | Won 11 |
| » Starters: Bill Singer vs Luke Walker | First | -- |
| Monday, July 19 |
| » Lost to Dodgers (51-45), 10-4 | Three Rivers Stadium (36-14) | 62-32 | |
| » Starters: Claude Osteen vs Nelson Briles | First | -- |
| Tuesday, July 20 |
| » Defeated Giants (58-39), 11-7 | Three Rivers Stadium (37-14) | 63-32 | |
| » Starters: Gaylord Perry vs Steve Blass | First | -- |
| Wednesday, July 21 |
| » Lost to Giants (59-39), 8-4 | Three Rivers Stadium (37-15) | 63-33 | |
| » Starters: Ron Bryant vs Bob Johnson | First | -- |
| Thursday, July 22 |
| » Lost to Giants (60-39), 8-7 | Three Rivers Stadium (37-16) | 63-34 | Lost 2 |
| » Starters: Juan Marichal vs Dock Ellis | First | -- |
| Friday, July 23 |
| » Defeated Padres (34-67), 4-0 | San Diego/Jack Murphy Stadium (2-1) | 64-34 | |
| » Starters: Bruce Kison vs Clay Kirby | First | -- |
| Saturday, July 24 |
| » Defeated Padres (34-68), 4-3 | San Diego/Jack Murphy Stadium (3-1) | 65-34 | Won 2 |
| » Starters: Steve Blass vs Dave Roberts | First | -- |
| Sunday, July 25 |
| » Lost to Padres (35-68), 2-1 | San Diego/Jack Murphy Stadium (3-2) | 65-35 | |
| » Starters: Bob Johnson vs Fred Norman | First | -- |
| » Lost to Padres (36-68), 2-0 | San Diego/Jack Murphy Stadium (3-3) | 65-36 | Lost 2 |
| » Starters: Bob Moose vs Steve Arlin | First | -- |
| Tuesday, July 27 |
| » Lost to Dodgers (54-49), 8-5 | Dodger Stadium (3-1) | 65-37 | Lost 3 |
| » Starters: Dock Ellis vs Al Downing | First | -- |
| Wednesday, July 28 |
| » Defeated Dodgers (54-50), 4-0 | Dodger Stadium (4-1) | 66-37 | |
| » Starters: Luke Walker vs Bill Singer | First | -- |
| Thursday, July 29 |
| » Defeated Dodgers (54-51), 8-5 | Dodger Stadium (5-1) | 67-37 | Won 2 |
| » Starters: Steve Blass vs Claude Osteen | First | -- |
| Friday, July 30 |
| » Lost to Giants (64-43), 5-2 | Candlestick Park (1-2) | 67-38 | |
| » Starters: Bruce Kison vs Gaylord Perry | First | -- |
| Saturday, July 31 |
| » Lost to Giants (65-43), 15-11 | Candlestick Park (1-3) | 67-39 | Lost 2 |
| » Starters: Bob Johnson vs Don Carrithers | First | -- |
| » Major-league debuts: Jim Barr (Giants) |
| Sunday, August 1 |
| » Lost to Giants (66-43), 11-7 | Candlestick Park (1-4) | 67-40 | Lost 3 |
| » Starters: Bob Moose vs Juan Marichal | First | -- |
| » Lost to Giants (67-43), 8-3 | Candlestick Park (1-5) | 67-41 | Lost 4 |
| » Starters: Dock Ellis vs Frank Reberger | First | -- |
| Tuesday, August 3 |
| » Defeated Expos (43-66), 10-6 | Parc Jarry (2-2) | 68-41 | |
| » Starters: Steve Blass vs Carl Morton | First | -- |
| Wednesday, August 4 |
| » Lost to Expos (44-66), 4-3 | Parc Jarry (2-3) | 68-42 | |
| » Starters: Luke Walker vs Bill Stoneman | First | -- |
| Thursday, August 5 |
| » Defeated Expos (44-67), 7-2 | Parc Jarry (3-3) | 69-42 | |
| » Starters: Bruce Kison vs John Strohmayer | First | -- |
| Friday, August 6 |
| » Lost to Phillies (49-63), 3-2 | Three Rivers Stadium (37-17) | 69-43 | |
| » Starters: Ken Reynolds vs Dock Ellis | First | -- |
| Saturday, August 7 |
| » Lost to Phillies (50-63), 5-3 | Three Rivers Stadium (37-18) | 69-44 | Lost 2 |
| » Starters: Rick Wise vs Bob Moose | First | -- |
| Sunday, August 8 |
| » Lost to Phillies (51-63), 3-2 | Three Rivers Stadium (37-19) | 69-45 | Lost 3 |
| » Starters: Woodie Fryman vs Steve Blass | First | -- |
| » Defeated Phillies (51-64), 4-0 | Three Rivers Stadium (38-19) | 70-45 | |
| » Starters: Chris Short vs Bob Johnson | First | -- |
| Tuesday, August 10 |
| » Lost to Cubs (63-51), 2-1 | Three Rivers Stadium (38-20) | 70-46 | |
| » Starters: Juan Pizarro vs Bruce Kison | First | -- |
| Wednesday, August 11 |
| » Defeated Cubs (63-52), 3-2 | Three Rivers Stadium (39-20) | 71-46 | |
| » Starters: Fergie Jenkins vs Dock Ellis | First | -- |
| Thursday, August 12 |
| » Lost to Cardinals (65-54), 3-2 | Three Rivers Stadium (39-21) | 71-47 | |
| » Starters: Steve Carlton vs Luke Walker | First | -- |
| Friday, August 13 |
| » Lost to Cardinals (66-54), 2-0 | Three Rivers Stadium (39-22) | 71-48 | Lost 2 |
| » Starters: Jerry Reuss vs Steve Blass | First | -- |
| Saturday, August 14 |
| » Lost to Cardinals (67-54), 11-0 | Three Rivers Stadium (39-23) | 71-49 | Lost 3 |
| » Starters: Bob Gibson vs Bob Johnson | First | -- |
| Sunday, August 15 |
| » Lost to Cardinals (68-54), 6-4 | Three Rivers Stadium (39-24) | 71-50 | Lost 4 |
| » Starters: Reggie Cleveland vs Bruce Kison | First | -- |
| Monday, August 16 |
| » Defeated Astros (60-61), 8-3 | Three Rivers Stadium (40-24) | 72-50 | |
| » Starters: Jack Billingham vs Dock Ellis | First | -- |
| Former Pirate Walter Mueller dies in St.Louis, MO at the age of 77. |
| Tuesday, August 17 |
| » Lost to Astros (61-61), 6-5 | Three Rivers Stadium (40-25) | 72-51 | |
| » Starters: Wade Blasingame vs Luke Walker | First | -- |
| Wednesday, August 18 |
| » Defeated Astros (61-62), 3-2 | Three Rivers Stadium (41-25) | 73-51 | |
| » Starters: Don Wilson vs Steve Blass | First | -- |
| Thursday, August 19 |
| » Defeated Reds (60-66), 5-1 | Riverfront Stadium (2-1) | 74-51 | Won 2 |
| » Starters: Bob Johnson vs Jim McGlothlin | First | -- |
| Friday, August 20 |
| » Lost to Reds (61-66), 6-0 | Riverfront Stadium (2-2) | 74-52 | |
| » Starters: Bruce Kison vs Ross Grimsley | First | -- |
| Saturday, August 21 |
| » Lost to Reds (62-66), 6-3 | Riverfront Stadium (2-3) | 74-53 | Lost 2 |
| » Starters: Dock Ellis vs Wayne Simpson | First | -- |
| Sunday, August 22 |
| » Lost to Reds (63-66), 6-3 | Riverfront Stadium (2-4) | 74-54 | Lost 3 |
| » Starters: Luke Walker vs Gary Nolan | First | -- |
| Monday, August 23 |
| » Defeated Braves (67-64), 4-3 | Atlanta-Fulton County Stadium (2-2) | 75-54 | |
| » Starters: Steve Blass vs Phil Niekro | First | -- |
| » Defeated Braves (67-65), 15-4 | Atlanta-Fulton County Stadium (3-2) | 76-54 | Won 2 |
| » Starters: Bob Moose vs Tom Kelley | First | -- |
| Tuesday, August 24 |
| » Lost to Braves (68-65), 15-5 | Atlanta-Fulton County Stadium (3-3) | 76-55 | |
| » Starters: Bob Johnson vs Mike McQueen | First | -- |
| Wednesday, August 25 |
| » Defeated Braves (68-66), 13-6 | Atlanta-Fulton County Stadium (4-3) | 77-55 | |
| » Starters: Bruce Kison vs Pat Jarvis | First | -- |
| Friday, August 27 |
| » Defeated Astros (63-68), 7-3 | Astrodome (3-1) | 78-55 | Won 2 |
| » Starters: Dock Ellis vs Jack Billingham | First | -- |
| Saturday, August 28 |
| » Lost to Astros (64-68), 4-0 | Astrodome (3-2) | 78-56 | |
| » Starters: Steve Blass vs Don Wilson | First | -- |
| Sunday, August 29 |
| » Defeated Astros (64-69), 5-2 | Astrodome (4-2) | 79-56 | |
| » Starters: Bob Johnson vs Wade Blasingame | First | -- |
| Monday, August 30 |
| » Defeated Phillies (57-76), 6-4 | Three Rivers Stadium (42-25) | 80-56 | Won 2 |
| » Starters: Chris Short vs Nelson Briles | First | -- |
| Tuesday, August 31 |
| » Defeated Phillies (57-77), 7-5 | Three Rivers Stadium (43-25) | 81-56 | Won 3 |
| » Starters: Barry Lersch vs Bob Moose | First | -- |
| Wednesday, September 1 |
| » Defeated Phillies (57-78), 10-7 | Three Rivers Stadium (44-25) | 82-56 | Won 4 |
| » Starters: Woodie Fryman vs Dock Ellis | First | -- |
| Friday, September 3 |
| » Lost to Expos (59-76), 6-4 | Three Rivers Stadium (44-26) | 82-57 | |
| » Starters: Steve Renko vs Steve Blass | First | -- |
| Saturday, September 4 |
| » Defeated Expos (59-77), 7-6 | Three Rivers Stadium (45-26) | 83-57 | |
| » Starters: Carl Morton vs Bob Johnson | First | -- |
| Sunday, September 5 |
| » Defeated Expos (59-78), 8-2 | Three Rivers Stadium (46-26) | 84-57 | Won 2 |
| » Starters: Bill Stoneman vs Bruce Kison | First | -- |
| » Major-league debuts: Terry Humphrey (Expos) |
| Monday, September 6 |
| » Defeated Cubs (73-67), 4-1 | Three Rivers Stadium (47-26) | 85-57 | Won 3 |
| » Starters: Juan Pizarro vs Nelson Briles | First | -- |
| » Defeated Cubs (73-68), 10-5 | Three Rivers Stadium (48-26) | 86-57 | Won 4 |
| » Starters: Ken Holtzman vs Luke Walker | First | -- |
| » Major-league debuts: Pat Bourque (Cubs) |
| Wednesday, September 8 |
| » Defeated Cubs (73-69), 10-1 | Three Rivers Stadium (49-26) | 87-57 | Won 5 |
| » Starters: Milt Pappas vs Steve Blass | First | -- |
| » Major-league debuts: Richie Zisk (Pirates) |
| Friday, September 10 |
| » Lost to Expos (62-79), 3-2 | Parc Jarry (3-4) | 87-58 | |
| » Starters: Bob Johnson vs Bill Stoneman | First | -- |
| Saturday, September 11 |
| » Lost to Expos (63-79), 4-1 | Parc Jarry (3-5) | 87-59 | Lost 2 |
| » Starters: Bruce Kison vs Ernie McAnally | First | -- |
| Sunday, September 12 |
| » Defeated Expos (63-80), 4-0 | Parc Jarry (4-5) | 88-59 | |
| » Starters: Nelson Briles vs Steve Renko | First | -- |
| Monday, September 13 |
| » Defeated Cubs (74-72), 5-1 | Wrigley Field (4-4) | 89-59 | Won 2 |
| » Starters: Steve Blass vs Milt Pappas | First | -- |
| Future Pirate Armando Rios is born in Santurce, P.R. |
| Tuesday, September 14 |
| » Defeated Cubs (74-73), 4-3 | Wrigley Field (5-4) | 90-59 | Won 3 |
| » Starters: Bob Johnson vs Fergie Jenkins | First | -- |
| Wednesday, September 15 |
| » Defeated Cardinals (82-67), 4-1 | Three Rivers Stadium (50-26) | 91-59 | Won 4 |
| » Starters: Steve Carlton vs Dock Ellis | First | -- |
| Thursday, September 16 |
| » Defeated Cardinals (82-68), 6-1 | Three Rivers Stadium (51-26) | 92-59 | Won 5 |
| » Starters: Jerry Reuss vs Luke Walker | First | -- |
| Friday, September 17 |
| » Lost to Mets (78-73), 3-0 | Three Rivers Stadium (51-27) | 92-60 | |
| » Starters: Gary Gentry vs Nelson Briles | First | -- |
| Saturday, September 18 |
| » Defeated Mets (78-74), 4-0 | |
