Elie, an American of Haitian heritage, grew up in New York City. He was named "Mario" for opera singer Mario Lanza. His father died after Elie graduated from college. He has a brother named Clark, who is an amateur basketball player, and a sister named Nancy. Elie attended Power Memorial Academy, where he was a teammate of Chris Mullin. Elie played streetball in Central Park and other locations in New York City during the 1980s, trying and failing several times to get into the NBA. His nickname on the New York playgrounds was 'The Jedi'. Eventually he played in Europe, most notably in Portugal and Ireland were he won the finals MVP with a 41 point performance, and later for the World Basketball League, and spent two years in the Continental Basketball Association with the Albany Patroons. In 1991, Elie played his first NBA games, first for the Golden State Warriors and Portland Trail Blazers briefly before being traded to the Houston Rockets in 1993.
Elie won NBA championships with the Rockets first in 1993-94 and again in 1994-95, making some incredible three-point field goals and getting the nicknames "Super Mario" and "Junkyard Dog."
Perhaps the highlight of Elie's career came when he hit a clutch three-pointer in game 7 of the Western Conference Semifinals against the Phoenix Suns to put the Rockets up by 3 with 7.1 seconds to play, sending Houston to the Western Conference Finals. The shot is called the 'kiss of death' by Rocket fans, as Elie made a taunting kissing gesture towards the Suns' bench shortly after the shot was made.
Elie played for the Rockets until 1997-98, when he was signed as a free agent with the San Antonio Spurs. He won a third NBA championship when he was part of the Spurs' championship team in 1999. Finally, after playing one season for the Phoenix Suns, he retired. On September 28, 2007, Elie was hired by the Dallas Mavericks as an assistant coach.
In 2007 Mario was inducted into the New York Basketball Hall of Fame.