They joined the Northern Union in 1901–02 and played for the single season in the Lancashire Senior Competition, which was effectively Division 2 (West).
They joined the ranks of the semi-professionals when they became members of the Northern Union for the 1901–02 season finishing in 12th position out of 13 clubs (with an unenviable record of only one win and one draw).
At the end of the 1901–02 season, the County Leagues elected 18 teams to join the new Division 2 (7 from Lancashire and 10 from Yorkshire and new member South Shields) with the existing second competition scrapped.
In the single season in which Altrincham played semi-professional rugby league, 1901–02, there are few records readily available.
The following are just a few of Altrincham's fixtures during the sole season in which they played semi-professional rugby league:[2][4][5]