The 1988–89 Georgetown Hoyas men's basketball team represented Georgetown University in the 1988–89 NCAA Division I college basketball season. John Thompson, coached them in his 17th season as head coach. They played their home games at the Capital Centre in Landover, Maryland. They were members of the Big East Conference and finished the season with a record of 29–5, 13–3 in Big East play. They finished as the Big East regular season champions and won the 1989 Big East men's basketball tournament, the sixth Big East tournament championship in Georgetown men's basketball history, defeating Syracuse in the final game. They were the No. 1 seed in the East Region of the 1989 NCAA Division I men's basketball tournament – the 11th of 14 consecutive Georgetown NCAA tournament appearances – and advanced to the East Region final before losing to the region's No. 2 seed, Duke. They were ranked No. 2 in the season's final Associated Press Poll and Coaches' Poll.
Player summaries
Since Patrick Ewing's graduation in May 1985, Georgetown had struggled to find a suitable replacement at center; sophomore Grady Mateen had been ineffective at the position in the 1985–86 season and had transferred to Ohio State after that year, while his successor Ben Gillery, who played in 1986–87 and 1987–88, had lacked offensive skill and seen only limited playing time. However, two talented centers joined the team this season. Freshman Alonzo Mourning, viewed nationally as "the next Patrick Ewing," arrived, and great things were expected of him and, because of him, for Georgetown men's basketball as a whole. Unheralded sophomore Dikembe Mutombo, a native of Zaire, in contrast, had spent his freshman year playing only intramural basketball in order to settle into life in the United States and focus on his academic studies and English language skills. Without any press attention, he was a virtual unknown outside of the Georgetown campus during his freshman year, and arrived on the varsity team for his sophomore season as a surprise to sportswriters and opposing teams. Mourning and Mutombo were among five future National Basketball Association (NBA) players on the 1988–89 squad.
Unaccustomed to American collegiate basketball, Mutombo appeared in 33 of the team's 34 games but started none of them and saw only limited playing time, averaging 11 minutes per game while he became acclimated to the college game in the United States. Although he averaged only 3.9 points and 3.3 rebounds per game for the season, these figures belied the scoring and defensive prowess he displayed on the court. Opponents found his close-range shots virtually impossible to stop, and he broke a 22-year-old school record with a 70.7% shooting average from the field; he scored in 23 games, and shot 100% from the field in ten of them. On defense, he showed himself to be a skilled shot blocker; never taught in Zaire to jump in anticipation of an opponent's shot, he simply stood his ground and waited for the opponent to commit to a shot before rising to swat it away. He blocked 75 shots during the season, and set a National Collegiate Athletic Association (NCAA) record with 12 shots blocked in a single game against St. John's. Despite his prowess, Mutumbo served solely as Mourning's backup; it would take an additional year before Thompson realized that Mourning and Mutumbo should be playing in the starting lineup at the same time.
Mourning, meanwhile, started all 34 games, averaging 29 minutes per game, and became a consistent scoring threat. Although he averaged only eight shots per game and led the team in scoring only six times, he averaged 13.2 points (along with 7.3 rebounds) per game. In his third game, playing against Saint Leo, he unofficially had the first triple double in Georgetown history. In his first ten games, he averaged 5.7 blocked shots per game, and in his eleventh, against Miami on January 7, 1989, he had 26 points, 17 rebounds, and six blocks. By the end of the season, he had blocked an NCAA-record 169 shots.