Marsh selected by the Atlanta Flames in the 1978 NHL Entry Draft, he scored 23 goals and added 175 assists in 1,086 NHL games, which is a record for fewest goals scored by a player who played at least 1,000 games. With Ottawa, Marsh made his only NHL All-Star appearance in 1993, scoring a goal for the victorious Wales Conference. Marsh was one of the last NHL players not to wear a helmet during league play.