107 patients scheduled to undergo anatomic double-bundle ACL reconstruction were randomized to have the procedure completed using either a semitendinosus and gracilis (STG) autograft or an irradiated STG allograft. The purpose of this study was to compare clinical examination results, patient-reported function, and the incidence of osteoarthritis development between groups over a mid-term follow-up period (5.5-8.0 years). Results demonstrated significantly better grading of subjective knee laxity and instability tests (Lachman, anterior drawer, pivot-shift) and significantly lower instrumented anteroposterior knee laxity on the KT-2000 arthrometer in the STG autograft group compared to the STG allograft group. All other measures assessed during clinical examination and patient-reported outcome measures demonstrated non-significant differences between groups at final follow-up. The incidence of OA development in the operative knee was significantly lower in the STG autograft group compared to the STG allograft group. Additionally, the graft failure rate (side-to-side difference >5mm on KT-2000) was significantly lower in the autograft group compared to the irradiated allograft group.