The 1988 Houston Astros season was the 27th season for the Major League Baseball (MLB) franchise located in Houston, Texas, their 24th as the Astros, 27th in the National League (NL), 20th in the NL West division, and 24rd at The Astrodome. The Astros entered the season having completed a 76–86 record and in third place, 14 games behind the division champion San Francisco Giants.

On April 5, Mike Scott made his second Opening Day start for the Astros. They hosted the San Diego Padres and won, 6–3, also the 2,000th victory in franchise history. During the amateur draft, the Astros selected outfielder Willie Ansley in the first round at 7th overall, infielder Dave Silvestri in the second round, and outfielder Kenny Lofton in the 17th round.

Pitcher Bob Knepper represented the Astros at the MLB All-Star Game, and played for the National League, his second career selection.

The Astros concluded the season with an 82–80 record, in fifth place and games behind the division champion and World Series champion Los Angeles Dodgers. Pitcher Nolan Ryan, who led the NL in strikeouts (228) for a second consecutive and in his final season as an Astro, made for the third consecutive season an Astros hurler led the league in strikeouts for the first time in franchise history

Offseason October 13, 1987: Catcher Ronn Reynolds was released by the Houston Astros. December 8, 1987: Third baseman Ed Whited was traded by the Houston Astros with pitcher Mike Stoker (minors) to the Atlanta Braves for Rafael Ramírez and cash. January 8, 1988: Pitcher Joaquín Andújar was signed as a free agent by the Astros. March 10, 1988: Ernie Camacho was signed as a free agent by the Astros. March 25, 1988: Robbie Wine was traded by the Astros to the Texas Rangers for Mike Loynd.

Regular season Summary April + Opening Day starting lineup Player Position 2 Gerald Young Center fielder 28 Billy Hatcher Left fielder 19 Bill Doran Second baseman 27 Glenn Davis First baseman 29 Denny Walling Third baseman 14 Alan Ashby Catcher 21 Terry Puhl Right fielder 16 Rafael Ramírez Shortstop 33 Mike Scott Pitcher Venue: Astrodome • Houston 6, San Diego 3 Sources:

On April 5, the Astros hosted the San Diego Padres on Opening Day, with right-hander Mike Scott making his second consecutive Opening Day start. In the top of the eighth, he surrendered two runs to the Padres. However, in the bottom of the inning, Kevin Bass' two-run single keyed a five-run rally which stood as Houston held on for the 6–3 win. Hence, the decision for the pitching win went to Scott. The Opening Day victory was also the 2,000th win in the history of the Houston Astros franchise.

On April 10, Kevin Bass, pinch hitting for right fielder Terry Puhl, hit the Astros' first-ever grand slam at Riverfront Stadium, and the Astros' first grand slam against Cincinnati since June 11, 1964, by Bob Aspromonte. Bass took Pat Perry deep in the top of the ninth inning as the Astros routed the Cincinnati Reds, 12–3. Glenn Davis (4) also homered. Mike Scott (2–0) earned the victory and complete game. This was also the fourth pinch-hit grand in Astros team history, with the most recent having been hit by teammate Craig Reynolds on April 12, 1986.

On April 27, Nolan Ryan came within two outs of his sixth no-hitter, maintaining a 2–0 lead over the Philadelphia Phillies in the top of the ninth, when Mike Schmidt singled into center field. In the bottom of the third inning, Bill Doran singled home Rafael Ramírez and Gerald Young, staking Houston to a 2–0 lead. Leading off the top of the ninth, Greg Gross' weak grounder to second allowed him to reach via an error, Schmidt singled, Juan Samuel struck out, and Von Hayes flied out. Lance Parrish then lined a two-run double to the left-center field gap to tie the game, with both runs being unearned. Ryan departed with a game score of 84. With the bases loaded in the bottom of the tenth, Glenn Davis scored as the walk-off run when Craig Reynolds hit into a fielder's choice. Dave Smith (1–1) retired the Phillies in order in the top of the tenth to earn the win.

May On May 8, Bill Doran tied a major league record among second basemen for a 9-inning game by turning six double plays.

Having gone more than two years since his most recent complete game, on May 13, Nolan Ryan went the distance to lead an 8–2 win over the Chicago Cubs. First baseman Glenn Davis collected four runs batted in (RBI), while Gerald Young stroked four hits to lead the Astros' offense.

With strong windy conditions all around Pittsburgh on May 23, the Astros held a 3–0 advantage going into the ninth inning. However, the game was called due to debris on the field at Three Rivers Stadium, and Mike Scott, who had held the Pirates scoreless for 8 innings, got the win.

June On June 6, Gerald Young became the first player in club history to reach base six times within a nine-inning game, and seventh overall. He reached on two singles and drew four base on balls. Young also looted three bases. Kevin Bass (12), Terry Puhl (3), and Billy Hatcher (16) each also performed larceny on the basepaths. Glenn Davis homered (12), and he, and Denny Walling each delivered three RBI to lead a 10–6 triumph over the Los Angeles Dodgers. Bob Knepper (7–1) allowed two runs in six frames to pick up the victory.

On June 12, Mike Scott was denied a second career no-hitter when Ken Oberkfell of the Atlanta Braves laced a clean single to right field with two outs in the ninth inning. Oberkfell's single was the only blemish on an otherwise stellar evening for Scott as he fanned eight, walked none, and led the Astros to victory, 5–0. Terry Puhl, Kevin Bass and Craig Reynolds each contributed three hits.

Craig Biggio made his major league debut at catcher on June 26 in a 6–0 win over the San Francisco Giants. Though he went hitless, Biggio stole second base and scored Houston's final run. Starting in place of an injured Alan Ashby, at the plate, Biggio also drew a walk, struck out and flied out. During the second inning, Biggio pegged José Uribe at third base for his first baserunner caught stealing. Biggio caught southpaw Jim Deshaies, also the winning pitcher.

On June 29, Biggio singled off Orel Hershiser during the third inning at the Astrodome for his first major league hit. Biggio also pilfered his second base. However, Hershiser (12–3) was dominant, hurling a two-hit, 2–0, shutout victory to outduel Ryan (5–6), who took the defeat. Ryan yielded four hits, four walks and two runs while striking out 10 over frames.

July During the nightcap of a doubleheader on July 1 at Shea Stadium, Biggio led off the top of the third inning with a short line drive off Rick Aguilera down the left field line for his first double and extra-base hit in the major leagues. During the top of the 13th inning, Kevin Bass singled in Billy Hatcher for the game-winning run and 6–5 triumph over the New York Mets. Rafael Ramírez recorded his first four-hit game as a member of the Astros.

Nolan Ryan: 100 wins each on two teams in two leagues During a nationally-televised broadcast on July 9, Nolan Ryan earned his 100th victory in an Astros uniform. He joined Cy Young as the only major leaguers to win 100 or more games each with two teams, along with 100 games each in the National and American Leagues. Ryan also had 138 wins as a member of the California Angels. Winless over his previous seven starts while carrying a personal seven-game losing streak to the Mets, Ryan allowed three runs on eight hits over frames, walking three and striking out five in a 6–3 Astros triumph. This was Ryan's 267th career win overall, ranking him 28th at the time.

Prior to the milestone win with Houston, Ryan (6–7) had already paralleled Young, Jim Bunning, Gaylord Perry, and Ferguson Jenkins with the feat of attaining 100 victories in each league. Moreover, Ryan became the seventh pitcher to have won at least 100 contests with two clubs, which included Young, Pud Galvin, John Clarkson, Bob Caruthers, Grover Cleveland Alexander, and Lefty Grove.

After a sluggish start by Ryan, the Astros found themselves in a three-run hole early against baseball's best team . However, four Astros responded with multi-hit games. In the second inning, Glenn Davis and Buddy Bell scorched back-to-back singles, prior to a ground rule double by Billy Hatcher that blazed over the center field wall. With one run in, Mets starter Sid Fernandez then halted additional damage by retiring Rafael Ramírez on a foul out, and struck out Biggio and Ryan.

In the third, a control lapse by Fernandez opened an opportunity Gerald Young, who led off the inning with a walk, stole second base, advanced to third on Gary Carter's throwing error, and scored on a wild pitch.

During his second inning of relief, Rick Aguilera (0–4) began to lose touch of his command, issuing three base on balls. Davis, Bell, and Hatcher each stung run-scoring singles. Biggio then drew a bases-loaded walk to force in the Astros' sixth run.

The Astros won their second game in a row after having lost six in a row at home for the first time since the outset of the 1983 campaign.

Ryan became the fifth moundsman to claim at least 100 victories for the Astros, following Larry Dierker, Don Wilson, J. R. Richard, and Joe Niekro. Biggio was the starting catcher as Ryan's batterymate, just his 12th contest as a major leaguer.

Rest of July On July 17, Glenn Davis connected for the 100th home run of his career, launching an offering from Mike Maddux deep to left field. This shot occurred in the top of the sixth at Veterans Stadium, breaking a scoreless tie.

August On August 22, Craig Biggio cranked his first major league home run, a tie-breaking solo shot served by Rich Gossage that touched off an extra-innings rally past the Chicago Cubs. Later in the top of the tenth inning, Gerald Young scored on a misplay of Kevin Bass' fly ball to center field, and Davis followed with a single to score Bass and raise the score, 9–6. In the bottom of the tenth, a balk called on Juan Agosto scored Shawon Dunston; however, Agosto buckled down to record the final out and preserve a 9–7 Houston triumph.

September Owing both to longevity and a propensity to issue walks, on September 8, Ryan furnished just the second complete game of his career without having issued any base on balls. This was the 184th complete game for "The Ryan Express." Ryan (11–11) led the Astros to a 2–1 win over Los Angeles at Dodger Stadium, yielding five hits and whiffing seven. Kirk Gibson's home run to deep right in the bottom of the fourth was the only play that prevented a shutout. In the top of the fourth, Ryan's batterymate, Alex Treviño, homered to temporarily inject a 1–0 lead for Houston. In the top of the eighth, Glenn Davis singled to right field and advanced on a throwing error by Mike Davis. Buddy Bell followed with a single to center which scored Davis for the go-ahead run, 2–1.

On September 14, Ryan maintained the momentum and delivered a second consecutive outing that featured a complete game without a base on balls. He struck out 13 as Houston defeated the Cincinnati Reds, 7–1.

The Astros became the fifth chapter of Orel Hershiser's scoreless innings streak on September 19, during which Hershiser totaled a major-league record 59. Los Angeles defeated Houston, 1–0, as Hershiser (22–8) fired a four-hit shutout. The only run of the contest arrived via a solo home run from John Shelby in the top of the seventh off a Danny Darwin offering (7–12), who allowed just three hits over six frames in relief of Nolan Ryan. Ryan, the Astros' starter for the game, departed after two innings due to a hamstring cramp. Prior to the injury, Ryan struck out four and issued a base on balls to Franklin Stubbs, hallmarking a career-long streak of 21 consecutive innings without having issued a base on balls, This would be his final appearance in an Astros uniform.