McNulty began his professional career on the Sunshine Tour before joining the European Tour in 1978, where he went on to become one of the leading players on the tour from the mid-1980s to the mid-1990s. He would go on to win 16 titles on the DP World Tour, finishing inside the top ten on the Order of Merit six times and featured in the top 10 of the Official World Golf Rankings for 83 weeks from 1987 to 1992.
McNulty has never won on the Legends Tour but has finished runner-up on three occasions. He narrowly missed out on Senior Major success in 2009, losing out in a play-off to Loren Roberts at Sunningdale at The Senior Open Championship.
McNulty made his second career ace at The Senior Open Championship presented by Rolex at Carnoustie in 2017 when he holed a 7-iron from 179 yards on No. 13 in the second round.
| Professional Wins | 59 |
| Turned Pro | 1977 |
