He was one of the leading players on the European Tour from the mid-1980s to the mid-1990s, and featured in the top 10 of the Official World Golf Ranking for 83 weeks from 1987 to 1992.

In the same year, he finished in the top-10 on the European Tour's Order of Merit for the first time, placing sixth.

When McNulty turned fifty and became eligible to play senior golf he chose to take part in the U.S.-based Champions Tour.

His first full season in 2004 was highly successful with three wins (including the Charles Schwab Cup Championship) and a seventh-place finish on the money list.

In November 1981, McNulty received serious facial and neck injuries when his car in high speed collided with a bus near his parents' farm in Zimbabwe, on his way to the ICL International in Johannesburg, South Africa.

[6] Despite his injuries, McNulty played in the 1981 South African Open the following month and won a tournament in Durban in January 1982, eight weeks after the accident.

He stated that his reason for doing so was his concern that as a non-resident Zimbabwean it could take him up to two years to get his passport renewed if he lost it.

Commentators elaborated that the farm that his family had been managing for 40-something years had been confiscated by the Mugabe regime.