and basketball career for the Georgetown University Hoyas. He led the nation in blocked shots his freshman year and was an AllAmerican his last year there.
Zo was selected in the 1992 NBA draft in the first round 2nd pick in the by the Charlotte Hornets behind Shaquille O'Neal and before Christian Laettner. Mourning was named to the league's all-rookie team in 1993 after averaging 21.0 points, 10.3 rebounds, and 3.47 blocks. He finished second to Shaquille O'Neal in rookie of the year voting.
In the 1994–95 season, Zo and teammate Larry Johnson led the Hornets to a 50-win season and reached the playoffs. Zo ranked first on the team in scoring (21.3 per game), rebounding (9.9 per game), blocked shots (2.92 per game), and field goal percentage (.519), and played in the 1995 NBA All-Star Game where he scored 10 points and grabbed 8 rebounds.
On November 3, 1995, after Mourning rejected Charlotte's contract extension, the Hornets traded him to the Miami Heat.
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.
In July 1996, Mourning signed a seven-year 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. 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, in Game 5 the Heat were eliminated by the Bulls.
Mourning signed a four-year deal with the New Jersey Nets in July 2003 as a free agent. On November 24, 2003, Mourning retired from the NBA due to complications from kidney disease.
On November 25, 2003, Mourning's cousin and a retired U. S. Marine, Jason Cooper, was visiting Mourning's gravely ill grandmother in the hospital. Mourning's father was present and informed Cooper that Zo was retiring that day from the NBA because of a life threatening kidney disease, focal segmental glomerulosclerosis, the same problem that Sean Elliott had in 1999. Cooper asked if there was anything he could do, and began to contemplate donating one of his kidneys to his estranged cousin, whom he had not seen in 25 years and whom he only knew through basketball. Cooper was tested for compatibility, along with many other family members and friends (including fellow NBA center and good friend Patrick Ewing); during his grandmother's funeral, Mourning received the news that Jason Cooper was a match. Mourning underwent a successful kidney transplant receiving Cooper's left kidney on December 19, 2003.
In 2004, he started practicing with the Nets again, and made the team's regular season roster during the 2004–05 season.
He did not play a significant role with the Nets and openly complained to the media that he wanted out of New Jersey, especially after the team traded away Kenyon Martin. Mourning was traded to the Toronto Raptors on December 17, 2004.] Mourning never reported to the Raptors, and was bought out of his contract on February 11, 2005. Raptors team officials later said that he did not meet the medical conditions to play for the team. Mourning then finished the season with the Heat being paid a second salary, the veteran's minimum.
Zo’s tenacity on defense twice earned him NBA Defensive Player of the Year Award and perennially placed him on the NBA AllDefensive Team. Mourning made a comeback and later won the 2006 NBA championship with the Heat. Mourning announced his retirement from the NBA on January 22, 2009. In his press conference he said, "At 38 I feel like I've physically done all I can for this game. One month later, the Heat announced that they would retire Mourning's number 33 jersey, making him the first Heat player to be so honored. The jersey retirement ceremony occurred on March 30, 2009, when the Heat hosted the Orlando Magic. During the extended halftime ceremony, Mourning was introduced by Florida Governor Charlie Crist; former Georgetown University basketball coach John Thompson; Basketball Hall of Famer Patrick Ewing; Heat players Dwyane Wade and Udonis Haslem; and Heat head coach Pat Riley.
Since June 2009, Mourning has served as VP of Player Programs and Development for the Heat which covers community outreach and mentoring young players.
In May 2009, he was named to the Hampton Roads Sports Hall of Fame, which honors athletes, coaches and administrators who contributed to sports in southeastern Virginia. In 2010, Mourning was inducted into the Virginia Sports Hall of Fame in recognition of his outstanding high school, collegiate, and professional career as well as his commitment to volunteer service in the communities in which he has lived and worked throughout his life. In August 2014, Mourning was inducted into the Naismith Memorial Basketball Hall of Fame, and in August 2019 he was inducted into the FIBA Hall of Fame.
In 1997, Mourning established Alonzo Mourning Charities Inc. to aid in the development of children and families living in at-risk situations and provides support and services that enhance the lives of youth of promise. After being diagnosed with focal glomerulosclerosis (FSGS), Mourning launched Zo's Fund for Life, a campaign which seeks to raise funds for research, education, and testing to fight focal glomerulosclerosis. Funds are allocated toward research for a cure, education for doctors and the general public, testing for early detection and a fund for those not able to afford medication.
In 2007, Mourning along with Andre Agassi, Muhammad Ali, Lance Armstrong, Warrick Dunn, Mia Hamm, Jeff Gordon, Tony Hawk, Andrea Jaeger, Jackie Joyner Kersee, Mario Lemieux, and Cal Ripken Jr. founded Athletes for Hope, a charitable organization, which helps professional athletes get involved in charitable causes and inspires millions of non-athletes to volunteer and support the community.
In 2003, he also founded the Overtown Youth Center for underprivileged kids, located in Miami, Florida. The program aims to inspire, empower, and enrich these children while teaching them to become positive contributing citizens.
In 2009, the Miami-Dade school board named a new high school in North Miami, Florida, in his honor, Alonzo and Tracy Mourning Senior High Biscayne Bay Campus.
Mourning has nine children: a son named Alonzo III ("Trey"), a daughter named Myka Sydney, and a second son named Alijah (born September 18, 2009). Like his father, Trey played for the Georgetown Hoyas basketball team, wearing his father's signature number 33 jersey. They reside in Pinecrest, Florida, where Mourning purchased a two story, 9,786-square-foot residence in 2012. His son Trey played basketball at Georgetown. On June 26, 2019, Trey was included on the Miami Heat roster for the 2019 NBA Summer League, and was later selected second overall by the Sioux Falls Skyforce of the NBA G League in the 2019 NBA G League draft.
In 2015, Mourning was one of eight Virginians honored in the Library of Virginia's "Strong Men & Women in Virginia History" for his charitable work and for his contributions to the sport of basketball.
March 3, 2022 Zo inducted into the Chesapeake Sports Club Legends of Honor.