Background: Hamstring (HS) autograft and bone-patellar tendon-bone allograft are the most common choice for reconstruction of anterior cruciate ligament (ACL).There was a little report about the clinical outcome and difference of arthroscopic ACL reconstruction using allograft and autograft.This study aimed to compare the clinical outcome of autograft and allograft reconstruction for ACL tears.Methods: A total of 106 patients who underwent surgery because of ACL tear were included in this study.The patients were randomly divided into two groups, including 53 patients in each group.The patients in group Ⅰ underwent standard ACL reconstruction with HS tendon autografts, while others in group Ⅱ underwent reconstruction with bone-patellar tendon-bone allograft.All the patients were followed up and analyzed;the mean follow-up was 81 months (range: 28-86 months).Clinical outcomes were evaluated using the Intational Knee Documentation Committee (IKDC), Lysholm scores, physical instability tests, and patient satisfaction questionnaires.The complication rates of both groups were compared.Tibial and femoral tunnel widening were assessed using lateral and anteroposterior radiographs.Results: At the end of follow-up, no significant differences were found between the groups in terms of IKDC, Lysholm scores, physical instability tests, patient satisfaction questionnaires, and incidences of arthrofibrosis.Tibial and femoral tunnel widening was less in the HS tendon autografts.This difference was more significant on the tibial side.Conclusions: In the repair of ACL tears, allograft reconstruction is as effective as the autograft reconstruction, but the allograft can lead to more tunnel widening evidently in the tibial tunnel, particularly.