Iain Duncan played for the Bowling Green State University Falcons for four years, being named to their "all century team" in 2000. Duncan started his National Hockey League career with the Winnipeg Jets in 1987. He would play his entire NHL career with the Jets.
He had a great rookie season in 1987-88 with the Jets, scoring 19 goals and 23 assists. In the next season he scored 14 goals and 30 assists. After that his play went downhill, and he started spending more time in the minor pros.
He would leave the NHL after the 1991 season. His NHL totals were 127 games, 34 goals, and 55 assists.
He retired from hockey after 1998.
He was named to the NHL All-Rookie Team in 1988. He was nicknamed Slam for his aggressive style of play.