We designed a prospective study to examine the influence of graft type (hamstring or patella tendon) on thigh muscle torque recovery after anterior cruciate ligament reconstruction. 60 patients undergoing ACL reconstruction, using a hamstring or patella tendon graft, were studied and 45 were followed up to 1 year. Concentric and eccentric quadriceps and hamstring torque were recorded, using an isokinetic dynamometer preoperatively, 6 and 12 months after ACL reconstruction. We found an improvement in all muscle functions in both the operated and unoperated legs during the recovery period. Graft type had no effect on recovery. During the first 6 months, torque was restored to preoperative levels and continued to improve in all muscles and actions between 6 months and 1 year.