Cunningham played one game in 1997 coming off the bench for his Ulster debut when Ulster were thrashed 56-3 by London Wasps. He came off the bench again in Ulster's 50-5 win against Morocco in 1998. He did it again by coming on against Leinster and against Toulouse. He was also part of the Ulster team that won the 1998-99 Heineken Cup against Colomiers in the final. He scored his first Ulster try against the Scarlets when the White men lost 26-27. He also scored against Connacht later that year when he was being given regular starts. He scored again against Neaths in 2002-2003 season and scored 5 tries in 2003-04. He scored 5 again in 2004-05. He then scored 10 points as a regular starter in Ulster's 2005/06 campaign in which they won the Celtic League. He scored 5 tries in 2006-07 and 1 in 2007-08. He only scored 1 in 2008-09 before playing his final Ulster game against Newport Gwent dragons which Ulster lost. Cunningham was then forced to retire due to injury.
Cunningham played with intensity and was an extremely fast man. He usually played at full-back but could play on the wing or in the centre. He was also a very good tackler most notably recognized when doing a try saving tackle against Munster.