The club plied its trade in the lower leagues of Luxembourgish football for most of its first sixty years, and only reached the third tier (the 'First Division') briefly in the 1970s, before relegation again.
In 1999–2000, Mamer was promoted to the second league, the Division of Honour, but was relegated immediately.
In its first season back in the higher division, Mamer finished fourth.
As the top league, the National Division, was expanding from twelve teams to fourteen, Mamer was given a chance of promotion by playing against US Rumelange, who had finished bottom of their National Division relegation group.
Mamer won on penalties, and was promoted to the National Division for the 2006–07 season.