| Thursday, January 1 |
| Future Pirate Gary Wilson is born in Arcata, CA. |
| Wednesday, January 14 |
| Future Pirate Steve Cooke is born in Lihue, HI. |
| Wednesday, January 21 |
| Future Pirate Jeff McCurry is born in Tokyo, Japan. |
| Monday, February 16 |
| Former Pirate Dick Conger dies in Los Angeles, CA at the age of 49. |
| Thursday, April 2 |
| Future Pirate Jon Lieber is born in Council Bluffs, IA. |
| Monday, April 6 |
| » Major-league debuts: Dick Such (Senators) |
| Tuesday, April 7 |
| » Lost to Mets (1-0), 5-3 | Forbes Field (0-1) | 0-1 | |
| » Starters: Tom Seaver vs Steve Blass | Third | 1 out |
| Wednesday, April 8 |
| Former Pirate Lee Handley dies in Pittsburgh, PA at the age of 57. |
| Thursday, April 9 |
| » Defeated Mets (1-1), 2-1 | Forbes Field (1-1) | 1-1 | |
| » Starters: Jerry Koosman vs Dock Ellis | Second | 1 out |
| Friday, April 10 |
| » Lost to Phillies (3-0), 2-0 | Shibe Park (0-1) | 1-2 | |
| » Starters: Bob Veale vs Woodie Fryman | Second | 2 out |
| Saturday, April 11 |
| » Defeated Phillies (3-1), 4-0 | Shibe Park (1-1) | 2-2 | |
| » Starters: Luke Walker vs Grant Jackson | Second | 1 out |
| Sunday, April 12 |
| » Defeated Phillies (3-2), 3-1 | Shibe Park (2-1) | 3-2 | Won 2 |
| » Starters: Steve Blass vs Jim Bunning | First | -- |
| Monday, April 13 |
| Future Pirate Ricardo Rincon is born in Veracruz, Mexico. |
| Tuesday, April 14 |
| » Defeated Mets (3-3), 6-4 | Shea Stadium (1-0) | 4-2 | Won 3 |
| » Starters: Dock Ellis vs Jerry Koosman | First | -- |
| Wednesday, April 15 |
| Former Pirate Ripper Collins dies in New Haven, NY at the age of 67. |
| Thursday, April 16 |
| » Defeated Mets (3-4), 7-4 | Shea Stadium (2-0) | 5-2 | Won 4 |
| » Starters: Bob Veale vs Gary Gentry | First | -- |
| Friday, April 17 |
| » Lost to Cardinals (6-2), 5-2 | Forbes Field (1-2) | 5-3 | |
| » Starters: George Culver vs Steve Blass | Second | 1 out |
| Saturday, April 18 |
| » Lost to Cardinals (7-2), 6-1 | Forbes Field (1-3) | 5-4 | Lost 2 |
| » Starters: Steve Carlton vs Luke Walker | Third | 2 out |
| Monday, April 20 |
| » Defeated Astros (7-7), 3-1 | Forbes Field (2-3) | 6-4 | |
| » Starters: Jim Bouton vs Dock Ellis | Third | 1½ out |
| Former Pirate Ed Mensor dies in Salem, OR at the age of 84. |
| Tuesday, April 21 |
| » Defeated Astros (7-8), 9-8 | Forbes Field (3-3) | 7-4 | Won 2 |
| » Starters: Larry Dierker vs Bob Veale | Second | ½ out |
| Wednesday, April 22 |
| » Defeated Astros (7-9), 6-1 | Forbes Field (4-3) | 8-4 | Won 3 |
| » Starters: Denny Lemaster vs Steve Blass | Second | ½ out |
| Thursday, April 23 |
| » Defeated Braves (5-10), 8-6 | Forbes Field (5-3) | 9-4 | Won 4 |
| » Starters: Pat Jarvis vs Luke Walker | Second | 1 out |
| Friday, April 24 |
| » Lost to Braves (6-10), 9-0 | Forbes Field (5-4) | 9-5 | |
| » Starters: Jim Nash vs Bob Moose | Third | 1 out |
| Saturday, April 25 |
| » Defeated Braves (6-11), 8-7 | Forbes Field (6-4) | 10-5 | |
| » Starters: George Stone vs Dock Ellis | Second | 1 out |
| Sunday, April 26 |
| » Lost to Braves (7-11), 2-0 | Forbes Field (6-5) | 10-6 | |
| » Starters: Phil Niekro vs Bob Veale | Third | 2 out |
| Monday, April 27 |
| » Lost to Cubs (12-3), 1-0 | Forbes Field (6-6) | 10-7 | Lost 2 |
| » Starters: Joe Decker vs Steve Blass | Third | 3 out |
| Tuesday, April 28 |
| » Defeated Cubs (12-4), 6-1 | Forbes Field (7-6) | 11-7 | |
| » Starters: Ken Holtzman vs Luke Walker | Second | 2 out |
| Wednesday, April 29 |
| » Lost to Cubs (13-4), 10-5 | Forbes Field (7-7) | 11-8 | |
| » Starters: Bill Hands vs Bob Moose | Second | 3 out |
| Thursday, April 30 |
| » Major-league debuts: Larry Gura (Cubs) |
| Friday, May 1 |
| » Lost to Reds (17-6), 6-4 | Crosley Field (0-1) | 11-9 | Lost 2 |
| » Starters: Dock Ellis vs Wayne Simpson | Second | 2½ out |
| Saturday, May 2 |
| » Lost to Reds (18-6), 7-2 | Crosley Field (0-2) | 11-10 | Lost 3 |
| » Starters: Bob Veale vs Jim McGlothlin | Second | 2½ out |
| Sunday, May 3 |
| » Lost to Reds (19-6), 11-7 | Crosley Field (0-3) | 11-11 | Lost 4 |
| » Starters: Steve Blass vs Jim Merritt | Fourth | 3 out |
| Monday, May 4 |
| » Lost to Braves (13-11), 5-3 | Atlanta-Fulton County Stadium (0-1) | 11-12 | Lost 5 |
| » Starters: Luke Walker vs Jim Nash | Third | 3 out |
| Tuesday, May 5 |
| » Lost to Braves (14-11), 12-6 | Atlanta-Fulton County Stadium (0-2) | 11-13 | Lost 6 |
| » Starters: Bob Moose vs George Stone | Third | 3 out |
| Wednesday, May 6 |
| » Lost to Braves (15-11), 3-0 | Atlanta-Fulton County Stadium (0-3) | 11-14 | Lost 7 |
| » Starters: Dock Ellis vs Phil Niekro | Fourth | 3½ out |
| Thursday, May 7 |
| » Defeated Astros (12-16), 9-5 | Astrodome (1-0) | 12-14 | |
| » Starters: Bob Veale vs Don Wilson | Third | 2½ out |
| Future Pirate Mark Smith is born in Pasadena, CA. |
| Friday, May 8 |
| » Lost to Astros (13-16), 7-5 | Astrodome (1-1) | 12-15 | |
| » Starters: Steve Blass vs Denny Lemaster | Third | 3½ out |
| Saturday, May 9 |
| » Defeated Astros (13-17), 6-3 | Astrodome (2-1) | 13-15 | |
| » Starters: Dock Ellis vs Tom Griffin | Third | 3½ out |
| Sunday, May 10 |
| » Lost to Astros (14-17), 9-2 | Astrodome (2-2) | 13-16 | |
| » Starters: Bob Moose vs Larry Dierker | Third | 3½ out |
| Monday, May 11 |
| » Defeated Reds (23-9), 4-1 | Forbes Field (8-7) | 14-16 | |
| » Starters: Jim McGlothlin vs Bob Veale | Second | 2½ out |
| Tuesday, May 12 |
| » Lost to Reds (24-9), 5-3 | Forbes Field (8-8) | 14-17 | |
| » Starters: Jim Merritt vs Steve Blass | Fourth | 3½ out |
| Wednesday, May 13 |
| » Defeated Cardinals (13-15), 5-1 | Busch Stadium II (1-0) | 15-17 | |
| » Starters: Bob Moose vs Bob Gibson | Third | 2½ out |
| Thursday, May 14 |
| » Lost to Cardinals (14-15), 11-7 | Busch Stadium II (1-1) | 15-18 | |
| » Starters: Dock Ellis vs George Culver | Fourth | 3 out |
| Friday, May 15 |
| » Lost to Expos (11-20), 2-1 | Forbes Field (8-9) | 15-19 | Lost 2 |
| » Starters: Dan McGinn vs Bob Veale | Fourth | 3 out |
| Saturday, May 16 |
| » Defeated Expos (11-21), 4-3 | Forbes Field (9-9) | 16-19 | |
| » Starters: Carl Morton vs Steve Blass | Fourth | 3 out |
| Sunday, May 17 |
| » Lost to Expos (12-21), 8-7 | Forbes Field (9-10) | 16-20 | |
| » Starters: Steve Renko vs Dave Giusti | Fourth | 3 out |
| Monday, May 18 |
| » Defeated Phillies (13-22), 2-1 | Forbes Field (10-10) | 17-20 | |
| » Starters: Jim Bunning vs Bob Moose | Fourth | 3 out |
| Tuesday, May 19 |
| » Lost to Phillies (14-22), 2-0 | Forbes Field (10-11) | 17-21 | |
| » Starters: Chris Short vs Dock Ellis | Fourth | 3 out |
| Wednesday, May 20 |
| » Defeated Phillies (14-23), 3-2 | Forbes Field (11-11) | 18-21 | |
| » Starters: Rick Wise vs Bob Veale | Fourth | 2½ out |
| Thursday, May 21 |
| » Lost to Expos (15-22), 7-6 | Parc Jarry (0-1) | 18-22 | |
| » Starters: Steve Blass vs Steve Renko | Fourth | 3 out |
| » Major-league debuts: Balor Moore (Expos) |
| Friday, May 22 |
| » Lost to Expos (16-22), 6-3 | Parc Jarry (0-2) | 18-23 | Lost 2 |
| » Starters: Bob Moose vs Bill Stoneman | Fourth | 4 out |
| Saturday, May 23 |
| » Defeated Expos (16-23), 8-4 | Parc Jarry (1-2) | 19-23 | |
| » Starters: Dock Ellis vs Dan McGinn | Fourth | 4 out |
| Sunday, May 24 |
| » Defeated Expos (16-24), 3-0 | Parc Jarry (2-2) | 20-23 | Won 2 |
| » Starters: Bob Veale vs Carl Morton | Fourth | 3½ out |
| Tuesday, May 26 |
| » Lost to Cubs (22-17), 6-3 | Wrigley Field (0-1) | 20-24 | |
| » Starters: Steve Blass vs Ken Holtzman | Fourth | 4½ out |
| Wednesday, May 27 |
| » Defeated Cubs (22-18), 4-0 | Wrigley Field (1-1) | 21-24 | |
| » Starters: Bob Moose vs Fergie Jenkins | Fourth | 3½ out |
| Thursday, May 28 |
| » Lost to Cubs (23-18), 8-7 | Wrigley Field (1-2) | 21-25 | |
| » Starters: Dock Ellis vs Bill Hands | Fourth | 4½ out |
| Friday, May 29 |
| » Defeated Giants (23-25), 6-3 | Forbes Field (12-11) | 22-25 | |
| » Starters: Rich Robertson vs Bob Veale | Fourth | 4 out |
| Saturday, May 30 |
| » Lost to Giants (24-25), 13-11 | Forbes Field (12-12) | 22-26 | |
| » Starters: Mike McCormick vs Steve Blass | Fourth | 4½ out |
| » Major-league debuts: Jim Nelson (Pirates) |
| Sunday, May 31 |
| » Defeated Giants (24-26), 7-3 | Forbes Field (13-12) | 23-26 | |
| » Starters: Juan Marichal vs Bob Moose | Third | 4½ out |
| Monday, June 1 |
| » Defeated Padres (22-32), 5-1 | Forbes Field (14-12) | 24-26 | Won 2 |
| » Starters: Danny Coombs vs Dock Ellis | Third | 3½ out |
| Tuesday, June 2 |
| » Lost to Padres (23-32), 14-8 | Forbes Field (14-13) | 24-27 | |
| » Starters: Gary Ross vs Bob Veale | Fourth | 4 out |
| Thursday, June 4 |
| » Lost to Dodgers (30-21), 5-0 | Forbes Field (14-14) | 24-28 | Lost 2 |
| » Starters: Claude Osteen vs Steve Blass | Fourth | 5 out |
| Friday, June 5 |
| » Defeated Dodgers (30-22), 3-0 | Forbes Field (15-14) | 25-28 | |
| » Starters: Joe Moeller vs Bob Moose | Fourth | 5 out |
| Saturday, June 6 |
| » Defeated Dodgers (30-23), 7-6 | Forbes Field (16-14) | 26-28 | Won 2 |
| » Starters: Don Sutton vs Dock Ellis | Third | 4 out |
| Sunday, June 7 |
| » Defeated Dodgers (30-24), 3-1 | Forbes Field (17-14) | 27-28 | Won 3 |
| » Starters: Alan Foster vs Bob Veale | Second | 4 out |
| Tuesday, June 9 |
| » Defeated Giants (25-31), 5-1 | Candlestick Park (1-0) | 28-28 | Won 4 |
| » Starters: Steve Blass vs Juan Marichal | Second | 4 out |
| Wednesday, June 10 |
| » Lost to Giants (26-31), 4-2 | Candlestick Park (1-1) | 28-29 | |
| » Starters: Bob Moose vs Gaylord Perry | Second | 4 out |
| Friday, June 12 |
| » Defeated Padres (26-36), 2-0 | San Diego/Jack Murphy Stadium (1-0) | 29-29 | |
| » Starters: Dock Ellis vs Dave Roberts | Second | 5 out |
| » Lost to Padres (27-36), 5-2 | San Diego/Jack Murphy Stadium (1-1) | 29-30 | |
| » Starters: Bob Veale vs Danny Coombs | Second | 5 out |
| Saturday, June 13 |
| » Defeated Padres (27-37), 7-2 | San Diego/Jack Murphy Stadium (2-1) | 30-30 | |
| » Starters: Steve Blass vs Al Santorini | Third | 5 out |
| Sunday, June 14 |
| » Lost to Padres (28-37), 2-1 | San Diego/Jack Murphy Stadium (2-2) | 30-31 | |
| » Starters: Bob Moose vs Clay Kirby | Third | 5 out |
| Monday, June 15 |
| » Defeated Dodgers (33-28), 5-2 | Dodger Stadium (1-0) | 31-31 | |
| » Starters: Jim Nelson vs Joe Moeller | Third | 4½ out |
| Tuesday, June 16 |
| » Lost to Dodgers (34-28), 1-0 | Dodger Stadium (1-1) | 31-32 | |
| » Starters: Bob Veale vs Don Sutton | Third | 4½ out |
| Wednesday, June 17 |
| » Lost to Dodgers (35-28), 4-0 | Dodger Stadium (1-2) | 31-33 | Lost 2 |
| » Starters: Dock Ellis vs Claude Osteen | Third | 5½ out |
| Friday, June 19 |
| » Defeated Expos (23-39), 8-4 | Forbes Field (18-14) | 32-33 | |
| » Starters: Dan McGinn vs Bob Moose | Third | 5 out |
| Saturday, June 20 |
| » Defeated Expos (23-40), 4-2 | Forbes Field (19-14) | 33-33 | Won 2 |
| » Starters: Carl Morton vs Steve Blass | Third | 5 out |
| Sunday, June 21 |
| » Lost to Expos (24-40), 3-2 | Forbes Field (19-15) | 33-34 | |
| » Starters: Rich Nye vs Bob Veale | Third | 4½ out |
| Monday, June 22 |
| » Lost to Cardinals (32-32), 6-1 | Forbes Field (19-16) | 33-35 | Lost 2 |
| » Starters: Jerry Reuss vs Dock Ellis | Third | 4 out |
| » Defeated Cardinals (32-33), 1-0 | Forbes Field (20-16) | 34-35 | |
| » Starters: Mike Torrez vs Jim Nelson | Third | 4 out |
| Tuesday, June 23 |
| » Defeated Cardinals (32-34), 7-2 | Forbes Field (21-16) | 35-35 | Won 2 |
| » Starters: Chuck Taylor vs Bob Moose | Third | 3 out |
| Wednesday, June 24 |
| » Defeated Cardinals (32-35), 4-3 | Forbes Field (22-16) | 36-35 | Won 3 |
| » Starters: Al Hrabosky vs Steve Blass | Third | 2 out |
| Thursday, June 25 |
| » Defeated Cardinals (32-36), 3-2 | Forbes Field (23-16) | 37-35 | Won 4 |
| » Starters: Steve Carlton vs Bob Veale | Third | 2 out |
| Saturday, June 27 |
| » Defeated Cubs (35-33), 2-1 | Forbes Field (24-16) | 38-35 | Won 5 |
| » Starters: Fergie Jenkins vs Dock Ellis | Second | 1½ out |
| Sunday, June 28 |
| » Defeated Cubs (35-34), 3-2 | Forbes Field (25-16) | 39-35 | Won 6 |
| » Starters: Bill Hands vs Bob Moose | Second | 2 out |
| » Defeated Cubs (35-35), 4-1 | Forbes Field (26-16) | 40-35 | Won 7 |
| » Starters: Milt Pappas vs Jim Nelson | Second | 2 out |
| » Major-league debuts: Gene Clines (Pirates) |
| Future Pirate Kevin Polcovich is born in Auburn, NY. |
| Monday, June 29 |
| » Lost to Mets (39-33), 3-2 | Shea Stadium (2-1) | 40-36 | |
| » Starters: Steve Blass vs Tom Seaver | Second | 2 out |
| Tuesday, June 30 |
| » Lost to Mets (40-33), 7-6 | Shea Stadium (2-2) | 40-37 | Lost 2 |
| » Starters: Bob Veale vs Jerry Koosman | Second | 2 out |
| Wednesday, July 1 |
| » Defeated Mets (40-34), 4-3 | Shea Stadium (3-2) | 41-37 | |
| » Starters: Dock Ellis vs Jim McAndrew | Second | 2 out |
| Friday, July 3 |
| » Defeated Cubs (36-38), 16-14 | Wrigley Field (2-2) | 42-37 | Won 2 |
| » Starters: Jim Nelson vs Bill Hands | First | -- |
| Saturday, July 4 |
| » Defeated Cubs (36-39), 10-6 | Wrigley Field (3-2) | 43-37 | Won 3 |
| » Starters: Steve Blass vs Ken Holtzman | Second | 1½ out |
| » Lost to Cubs (37-39), 7-2 | Wrigley Field (3-3) | 43-38 | |
| » Starters: Bob Veale vs Milt Pappas | Second | 1½ out |
| Sunday, July 5 |
| » Defeated Cubs (37-40), 5-2 | Wrigley Field (4-3) | 44-38 | |
| » Starters: Dock Ellis vs Fergie Jenkins | Second | 1½ out |
| Monday, July 6 |
| » Defeated Phillies (34-46), 7-5 | Shibe Park (3-1) | 45-38 | Won 2 |
| » Starters: Jim Nelson vs Jim Bunning | Second | 1½ out |
| Tuesday, July 7 |
| » Defeated Phillies (34-47), 4-2 | Shibe Park (4-1) | 46-38 | Won 3 |
| » Starters: Bob Veale vs Chris Short | Second | 1½ out |
| Former Pirate Harry Wolter dies in Palo Alto, CA at the age of 86. |
| Wednesday, July 8 |
| » Lost to Phillies (35-47), 2-0 | Shibe Park (4-2) | 46-39 | |
| » Starters: Steve Blass vs Rick Wise | Second | 1½ out |
| Thursday, July 9 |
| » Defeated Cardinals (39-44), 6-0 | Busch Stadium II (2-1) | 47-39 | |
| » Starters: Dock Ellis vs Steve Carlton | Second | 1½ out |
| Friday, July 10 |
| » Defeated Cardinals (39-45), 6-2 | Busch Stadium II (3-1) | 48-39 | Won 2 |
| » Starters: Jim Nelson vs Bob Gibson | Second | 1½ out |
| Saturday, July 11 |
| » Defeated Cardinals (39-46), 8-7 | Busch Stadium II (4-1) | 49-39 | Won 3 |
| » Starters: Bob Veale vs Jerry Reuss | First | -- |
| Sunday, July 12 |
| » Defeated Cardinals (39-47), 7-6 | Busch Stadium II (5-1) | 50-39 | Won 4 |
| » Starters: Steve Blass vs Mike Torrez | First | -- |
| » Major-league debuts: Ed Crosby (Cardinals) |
| Thursday, July 16 |
| » Lost to Reds (63-26), 3-2 | Three Rivers Stadium (0-1) | 50-40 | |
| » Starters: Gary Nolan vs Dock Ellis | First | -- |
| Friday, July 17 |
| » Defeated Reds (63-27), 4-3 | Three Rivers Stadium (1-1) | 51-40 | |
| » Starters: Wayne Simpson vs Jim Nelson | First | -- |
| Saturday, July 18 |
| » Lost to Reds (64-27), 3-1 | Three Rivers Stadium (1-2) | 51-41 | |
| » Starters: Jim Merritt vs Bob Veale | First | -- |
| Sunday, July 19 |
| » Defeated Reds (64-28), 7-3 | Three Rivers Stadium (2-2) | 52-41 | |
| » Starters: Jim McGlothlin vs Luke Walker | First | -- |
| Monday, July 20 |
| » Lost to Astros (40-53), 5-4 | Astrodome (2-3) | 52-42 | |
| » Starters: Dock Ellis vs Denny Lemaster | First | -- |
| Tuesday, July 21 |
| » Lost to Astros (41-53), 3-1 | Astrodome (2-4) | 52-43 | Lost 2 |
| » Starters: Jim Nelson vs Don Wilson | First | -- |
| Wednesday, July 22 |
| » Defeated Braves (46-48), 5-3 | Three Rivers Stadium (3-2) | 53-43 | |
| » Starters: George Stone vs Bruce DalCanton | First | -- |
| Thursday, July 23 |
| » Defeated Braves (46-49), 6-5 | Three Rivers Stadium (4-2) | 54-43 | Won 2 |
| » Starters: Jim Nash vs Luke Walker | First | -- |
| Friday, July 24 |
| » Defeated Astros (43-54), 11-0 | Three Rivers Stadium (5-2) | 55-43 | Won 3 |
| » Starters: Tom Griffin vs Dock Ellis | First | -- |
| Saturday, July 25 |
| » Lost to Astros (44-54), 8-4 | Three Rivers Stadium (5-3) | 55-44 | |
| » Starters: Ron Cook vs Bob Veale | First | -- |
| Sunday, July 26 |
| » Lost to Astros (45-54), 6-4 | Three Rivers Stadium (5-4) | 55-45 | Lost 2 |
| » Starters: Don Wilson vs Jim Nelson | First | -- |
| Tuesday, July 28 |
| » Defeated Reds (70-32), 4-3 | Riverfront Stadium (1-0) | 56-45 | |
| » Starters: Bruce DalCanton vs Jim McGlothlin | First | -- |
| Wednesday, July 29 |
| » Lost to Reds (71-32), 4-3 | Riverfront Stadium (1-1) | 56-46 | |
| » Starters: Dock Ellis vs Gary Nolan | First | -- |
| Thursday, July 30 |
| » Lost to Reds (72-32), 8-4 | Riverfront Stadium (1-2) | 56-47 | Lost 2 |
| » Starters: Bob Veale vs Tony Cloninger | First | -- |
| Friday, July 31 |
| » Lost to Braves (50-53), 4-3 | Atlanta-Fulton County Stadium (0-4) | 56-48 | Lost 3 |
| » Starters: Jim Nelson vs Pat Jarvis | Second | 1½ out |
| Saturday, August 1 |
| » Defeated Braves (50-54), 20-10 | Atlanta-Fulton County Stadium (1-4) | 57-48 | |
| » Starters: Bruce DalCanton vs George Stone | Second | 1½ out |
| Sunday, August 2 |
| » Defeated Braves (50-55), 10-7 | Atlanta-Fulton County Stadium (2-4) | 58-48 | Won 2 |
| » Starters: Dock Ellis vs Jim Nash | First | -- |
| Former Pirate Mike Cvengros dies in Hot Springs, AR at the age of 69. |
| Monday, August 3 |
| » Lost to Expos (47-60), 8-0 | Parc Jarry (2-3) | 58-49 | |
| » Starters: Bob Moose vs Dan McGinn | First | -- |
| Tuesday, August 4 |
| » Defeated Expos (47-61), 4-2 | Parc Jarry (3-3) | 59-49 | |
| » Starters: Bob Veale vs Mike Marshall | First | -- |
| Wednesday, August 5 |
| » Defeated Phillies (49-57), 4-0 | Three Rivers Stadium (6-4) | 60-49 | Won 2 |
| » Starters: Rick Wise vs Luke Walker | First | -- |
| Thursday, August 6 |
| » Defeated Phillies (49-58), 4-0 | Three Rivers Stadium (7-4) | 61-49 | Won 3 |
| » Starters: Jim Bunning vs Dock Ellis | First | -- |
| » Defeated Phillies (49-59), 8-3 | Three Rivers Stadium (8-4) | 62-49 | Won 4 |
| » Starters: Bill Champion vs Bruce DalCanton | First | -- |
| Friday, August 7 |
| » Defeated Mets (58-51), 6-1 | Three Rivers Stadium (9-4) | 63-49 | Won 5 |
| » Starters: Jim McAndrew vs Bob Moose | First | -- |
| Saturday, August 8 |
| » Lost to Mets (59-51), 12-9 | Three Rivers Stadium (9-5) | 63-50 | |
| » Starters: Jerry Koosman vs Bob Veale | First | -- |
| Sunday, August 9 |
| » Defeated Mets (59-52), 8-3 | Three Rivers Stadium (10-5) | 64-50 | |
| » Starters: Nolan Ryan vs Luke Walker | First | -- |
| Monday, August 10 |
| » Lost to Mets (60-52), 10-2 | Three Rivers Stadium (10-6) | 64-51 | |
| » Starters: Tom Seaver vs Dock Ellis | First | -- |
| Tuesday, August 11 |
| » Lost to Dodgers (64-49), 5-4 | Three Rivers Stadium (10-7) | 64-52 | Lost 2 |
| » Starters: Claude Osteen vs Bruce DalCanton | First | -- |
| Wednesday, August 12 |
| » Lost to Dodgers (65-49), 11-4 | Three Rivers Stadium (10-8) | 64-53 | Lost 3 |
| » Starters: Bill Singer vs Bob Moose | First | -- |
| » Major-league debuts: Charlie Hough (Dodgers) |
| Friday, August 14 |
| » Defeated Padres (46-72), 2-1 | Three Rivers Stadium (11-8) | 65-53 | |
| » Starters: Dave Roberts vs Steve Blass | First | -- |
| » Defeated Padres (46-73), 10-1 | Three Rivers Stadium (12-8) | 66-53 | Won 2 |
| » Starters: Pat Dobson vs Luke Walker | First | -- |
| Saturday, August 15 |
| » Defeated Padres (46-74), 9-3 | Three Rivers Stadium (13-8) | 67-53 | Won 3 |
| » Starters: Earl Wilson vs Bob Veale | First | -- |
| Sunday, August 16 |
| » Lost to Padres (47-74), 8-6 | Three Rivers Stadium (13-9) | 67-54 | |
| » Starters: Danny Coombs vs Bruce DalCanton | First | -- |
| Monday, August 17 |
| » Lost to Giants (60-60), 5-4 | Three Rivers Stadium (13-10) | 67-55 | Lost 2 |
| » Starters: Gaylord Perry vs Bob Moose | First | -- |
| Tuesday, August 18 |
| » Defeated Giants (60-61), 6-2 | Three Rivers Stadium (14-10) | 68-55 | |
| » Starters: Skip Pitlock vs Steve Blass | First | -- |
| Wednesday, August 19 |
| » Lost to Giants (61-61), 7-4 | Three Rivers Stadium (14-11) | 68-56 | |
| » Starters: Juan Marichal vs Luke Walker | First | -- |
| Friday, August 21 |
| » Lost to Dodgers (70-52), 2-1 | Dodger Stadium (1-3) | 68-57 | Lost 2 |
| » Starters: Bob Veale vs Claude Osteen | First | -- |
| Saturday, August 22 |
| » Defeated Dodgers (70-53), 2-1 | Dodger Stadium (2-3) | 69-57 | |
| » Starters: Bob Moose vs Don Sutton | First | -- |
| Sunday, August 23 |
| » Defeated Dodgers (70-54), 11-0 | Dodger Stadium (3-3) | 70-57 | Won 2 |
| » Starters: Steve Blass vs Alan Foster | First | -- |
| Tuesday, August 25 |
| » Lost to Padres (49-79), 4-3 | San Diego/Jack Murphy Stadium (2-3) | 70-58 | |
| » Starters: Luke Walker vs Dave Roberts | First | -- |
| Wednesday, August 26 |
| » Lost to Padres (50-79), 2-1 | San Diego/Jack Murphy Stadium (2-4) | 70-59 | Lost 2 |
| » Starters: Fred Cambria vs Pat Dobson | First | -- |
| Friday, August 28 |
| » Lost to Giants (66-63), 5-1 | Candlestick Park (1-2) | 70-60 | Lost 3 |
| » Starters: Bob Moose vs Juan Marichal | First | -- |
| Saturday, August 29 |
| » Lost to Giants (67-63), 10-9 | Candlestick Park (1-3) | 70-61 | Lost 4 |
| » Starters: Steve Blass vs Skip Pitlock | First | -- |
| Sunday, August 30 |
| » Lost to Giants (68-63), 7-3 | Candlestick Park (1-4) | 70-62 | Lost 5 |
| » Starters: Luke Walker vs Frank Reberger | First | -- |
| » Lost to Giants (69-63), 2-1 | Candlestick Park (1-5) | 70-63 | Lost 6 |
| » Starters: Fred Cambria vs Ron Bryant | First | -- |
| Tuesday, September 1 |
| » Defeated Expos (57-76), 8-4 | Parc Jarry (4-3) | 71-63 | |
| » Starters: Bob Veale vs Bill Stoneman | First | -- |
| Wednesday, September 2 |
| » Lost to Expos (58-76), 10-7 | Parc Jarry (4-4) | 71-64 | |
| » Starters: Bob Moose vs Carl Morton | First | -- |
| Future Pirate Sean Lawrence is born in Oak Park, IL. |
| Friday, September 4 |
| » Defeated Phillies (63-73), 4-3 | Three Rivers Stadium (15-11) | 72-64 | |
| » Starters: Rick Wise vs Steve Blass | First | -- |
| Saturday, September 5 |
| » Defeated Phillies (63-74), 6-4 | Three Rivers Stadium (16-11) | 73-64 | Won 2 |
| » Starters: Barry Lersch vs Fred Cambria | First | -- |
| » Major-league debuts: Joe Lis and Ken Reynolds (Phillies) |
| Sunday, September 6 |
| » Defeated Phillies (63-75), 4-3 | Three Rivers Stadium (17-11) | 74-64 | Won 3 |
| » Starters: Jim Bunning vs Luke Walker | First | -- |
| Monday, September 7 |
| » Defeated Cubs (72-67), 8-3 | Three Rivers Stadium (18-11) | 75-64 | Won 4 |
| » Starters: Milt Pappas vs Bob Moose | First | -- |
| » Lost to Cubs (73-67), 9-2 | Three Rivers Stadium (18-12) | 75-65 | |
| » Starters: Fergie Jenkins vs Bob Veale | First | -- |
| » Major-league debuts: Ed Acosta (Pirates) |
| Tuesday, September 8 |
| » Lost to Cubs (74-67), 10-3 | Three Rivers Stadium (18-13) | 75-66 | Lost 2 |
| » Starters: Bill Hands vs Steve Blass | First | -- |
| » Major-league debuts: Milt May (Pirates) |
| Wednesday, September 9 |
| » Lost to Cardinals (68-75), 6-4 | Three Rivers Stadium (18-14) | 75-67 | Lost 3 |
| » Starters: Frank Bertaina vs Fred Cambria | First | -- |
| Future Pirate Dan Miceli is born in Newark, NJ. |
| Thursday, September 10 |
| » Defeated Cardinals (68-76), 2-0 | Three Rivers Stadium (19-14) | 76-67 | |
| » Starters: Nelson Briles vs Luke Walker | First | -- |
| Friday, September 11 |
| » Major-league debuts: John Vukovich (Phillies) |
| Saturday, September 12 |
| » Defeated Cubs (75-69), 5-4 | Wrigley Field (5-3) | 77-67 | Won 2 |
| » Starters: Bob Moose vs Fergie Jenkins | First | -- |
| Sunday, September 13 |
| » Lost to Cubs (76-69), 3-2 | Wrigley Field (5-4) | 77-68 | |
| » Starters: Steve Blass vs Bill Hands | First | -- |
| Tuesday, September 15 |
| » Defeated Phillies (66-82), 8-3 | Shibe Park (5-2) | 78-68 | |
| » Starters: Luke Walker vs Barry Lersch | First | -- |
| » Major-league debuts: Bill Laxton (Phillies) |
| Wednesday, September 16 |
| » Defeated Phillies (66-83), 5-3 | Shibe Park (6-2) | 79-68 | Won 2 |
| » Starters: Bob Moose vs Jim Bunning | First | -- |
| Thursday, September 17 |
| » Lost to Phillies (67-83), 3-2 | Shibe Park (6-3) | 79-69 | |
| » Starters: Dock Ellis vs Chris Short | First | -- |
| Friday, September 18 |
| » Defeated Mets (78-72), 3-2 | Shea Stadium (4-2) | 80-69 | |
| » Starters: Steve Blass vs Jim McAndrew | First | -- |
| Saturday, September 19 |
| » Defeated Mets (78-73), 2-1 | Shea Stadium (5-2) | 81-69 | Won 2 |
| » Starters: Luke Walker vs Gary Gentry | First | -- |
| Sunday, September 20 |
| » Lost to Mets (79-73), 4-1 | Shea Stadium (5-3) | 81-70 | |
| » Starters: Bob Moose vs Jerry Koosman | First | -- |
| » Defeated Mets (79-74), 9-5 | Shea Stadium (6-3) | 82-70 | |
| » Starters: Fred Cambria vs Tom Seaver | First | -- |
| Tuesday, September 22 |
| » Lost to Expos (68-85), 1-0 |
