After some years of success playing at a junior level, the club was given senior status by the Ulster Branch in the 1928/29 season and celebrated by winning the senior league at its first attempt. Up until World War II, Civil Service teams enjoyed high placings in the league tables but struggled to convert good performances in to trophies.

Playing performances however improved steadily throughout the 1950s and 1960s, Service junior teams won league and cup competitions and the 1st XV won the Ulster Senior League in 1969-70. They also enjoyed something of a tradition in sevens winning a number of the premier competitions in Ulster at that time.

In more recent times Civil Service has competed at more modest levels as it no longer has senior status. However, the Club also enjoyed successes in league and cup competitions in the 1990s. The 1st XV won the McCrea Cup in 1998, followed by triumphs in Qualifying League 3 and the North Down Cup.

The Club has a long and proud tradition of producing players, referees and officials who gained international and representative recognition. Several players were capped by Ulster and Ireland, while others who passed through the ranks of Service teams achieved similar honours, including British Lions status. In total, the Club has provided 4 Presidents of the Ulster Branch and others who served on various committees.

The Clubs most distinguished son was perhaps Dudley Higgins, an accomplished full back, who gained caps during the 1948 Five Nations Championship, and indoing so became one of the elite band of players who have won a Grand Slam for ireland. Dudley went on to become President of the Ulster Branch in 1960/61 and of the IRFU in 1976-77.