Hansen was selected by the Utah Jazz in the third round of the 1983 NBA draft, the 54th overall pick. Hansen appeared in 55 games during his rookie season with the Jazz, averaging 2.7 points per game and 7.6 minutes per game. By the 1985–86 season, Hansen was a regular starter for the Jazz. He was also one of three Jazz players named NBA Player of the Week (March 6, 1986) during the season, joining teammates John Stockton and Karl Malone. Hansen's highest scoring average, 9.7 points per game, came during the 1986–87 season. During the 1990 All-Star weekend, Hansen participated in the three-point challenge, finishing fourth.