Foster was born in Oakland, California and attended Skyline High School where he played alongside future NBA point guard Gary Payton.

He began his collegiate basketball career at UCLA, playing for the Bruins his freshman and sophomore years before transferring to UTEP.

Foster helped lead the Miners to two WAC titles, and as a senior he averaged 15.0 points and 6.3 rebounds per game.

He spent 13 seasons (1990–2003) in the NBA as a member of the Washington Bullets, Atlanta Hawks, Milwaukee Bucks, Chicago Bulls, Minnesota Timberwolves, Utah Jazz, Seattle SuperSonics, Los Angeles Lakers, and Toronto Raptors.

On June 8, 2018, the Atlanta Hawks hired Foster as an assistant coach, a position he held for the next season as well.