Over a ten-year career, he played for five teams—the Knicks, the Denver Nuggets, the Washington Bullets, the Detroit Pistons, and the Chicago Bulls.

Walker was selected to the 1984 NBA All-Rookie team, and was among the league leaders during his career in assists and steals.

Later that same year, he was named the interim head coach of the Washington Mystics of the WNBA, replacing Nancy Darsch who resigned during the season.

[2] He remained in Washington as director of player personnel and later head scout before joining the Hornets as assistant coach.

On March 27, 2018, Walker was named the head men's basketball coach at the University of Arkansas at Little Rock.