Miami Heat (1995–2003)
On November 3, 1995, after Mourning rejected Charlotte's contract extension offer worth an average of $11.2 million for seven years and knowing they would not be able to re-sign him, the Hornets traded him, along with reserves Pete Myers and LeRon Ellis to the Miami Heat in exchange for Glen Rice, Matt Geiger, Khalid Reeves and a first-round pick in the 1996 NBA draft.
Mourning would immediately serve as the centerpiece of the Pat Riley-coached Heat, and in his first season in Miami he averaged 23.2 points, 10.4 rebounds and 2.7 blocks per game as Miami made the playoffs before being swept in the first round by the 72-win Bulls. Mourning played in the 1996 NBA All-Star Game and was joined by All-Star point guard Tim Hardaway who arrived through a mid-season trade.
In July 1996, Mourning signed a seven-year, $105 million contract with the Heat. In the 1996–97 season, the Heat would go on to win a then franchise-record 61 games, finishing second in the Eastern Conference behind the defending champions Bulls, while Mourning averaged 19.8 points, 9.9 rebounds and 2.9 blocks per game. In the playoffs, Miami defeated the Orlando Magic in five games, and advanced to the conference semifinals against the Knicks, where the rivalry between the Heat and the New York Knicks intensified. The Knicks took a 3–1 series lead, but following a brawl between Charlie Ward and P. J. Brown late in Game 5, multiple suspensions were handed down. Mourning scored 28 points in Game 6, followed by a 22-point, 12-rebound performance in Game 7 to help Miami advance to the Eastern Conference Finals, a franchise first, to face Chicago. The Bulls took a 3–0 series lead, and Mourning guaranteed a victory in Game 4 as the Heat won 87–80. However, with a 100–87 loss in Game 5, the Heat were eliminated by the Bulls.
In the 1997–98 season, Mourning played 58 games and averaged 19.2 points, 9.6 rebounds and 2.2 blocks per game as the Heat won 55 games. However, Miami lost in the first round to the Knicks, with Mourning missing the deciding Game 5 due to a suspension caused by a fight between Mourning and former teammate Larry Johnson in Game 4. The brawl also involved Knicks head coach Jeff Van Gundy, who was seen dangling on Mourning's leg in an attempt to break up the fight. The following season, the Heat won 31 games in a lockout-shortened 50-game schedule, and Mourning won his first of two consecutive Defensive Player of the Year awards after leading the league in blocks with 3.9 per game. Despite finishing with the best record in the Eastern Conference, the Heat once again fell short to the Knicks in the first round, with Allan Houston securing the series victory with a last-second jumper in Game 5. Mourning again led the NBA in blocks in the 1999–2000 season, this time with a 3.7 average, and won Defensive Player of the Year. Miami finished the regular season with 52 wins and faced the Knicks in the second round. But for a third straight season, the Heat lost to the Knicks in a winner-take-all game, this time in Game 7.
Shortly after playing for the gold medal-winning U.S. national team in the 2000 Summer Olympics, Mourning was diagnosed with a serious kidney disease. Initially deemed out for the remainder of the season, Mourning returned for the final 13 games, helping the Heat win 50 games despite playing limited minutes. However, Miami was swept 3–0 in the first round by the Hornets. In the 2001–02 season, Mourning played 75 games and averaged 15.7 points, 8.4 rebounds and 2.5 blocks per game, earning his final All-Star nod. Despite that, the Heat missed the playoffs with a 36–46 record. Mourning missed the entire 2002–03 season as he continued to deal with a serious kidney disorder, and without their star center, the Heat won only 25 games and missed the playoffs again.