In the 2005–2006 season, Rumelange finished eleventh in the National Division. It was almost impossible for Rumelange to avoid fourth place, and they were pitted against FC Mamer in a relegation play-off. Rumelange lost on penalties, and were relegated to the Division of Honour. They won promotion to the highest level again at the end of the 2007–2008 season.
US Rumelange have qualified for UEFA European competition four times. However, they have been generally unsuccessful; during their 1972–73 UEFA Cup campaign, they suffered a 21–0 aggregate loss to Feyenoord, a record defeat that has not been eclipsed in any UEFA cup competition. It has not been matched either, except for when, one year earlier, Chelsea had beaten Jeunesse Hautcharage by the same aggregate scoreline.
- First round (2): 1968–69, 1975–76
- First round (2): 1970–71, 1972–73
- As of 29 August 2020
Note: Flags indicate national team as defined under FIFA eligibility rules. Players may hold more than one non-FIFA nationality.