In 1989 Risborough accepted an invitation to join the South Midlands League and were placed in Division One. In the first two seasons the club struggled, finishing second from bottom and had to apply for re-election. However, at the end of season 1992–93, the club gained promotion to the Senior Division under the management of Frank Carter. At the start of the 1997–98 season, with the merger of the Souith Midlands league and the London Spartan League, the club became founder members of the Spartan South Midlands League Senior Division. The club remained in the Senior Division, which was later renamed Division One, until the end of the 2002–03 season, when they finished bottom and were relegated to Division Two.