Abstract:[Objective] To compare the clinical outcomes of arthroscopic single-bundle anterior cruciate ligament (ACL) reconstruc- tion with hamstring tendon (HT) versus quadriceps tendon (QT) autografts. [Methods] A total of 86 patients received arthroscopic singlebundle ACL reconstruction in our hospital from November 2016 to December 2019. Based on doctor-patient communication, 43 patients had HT used for ACL reconstruction, while the remaining 43 patients had QT used. The perioperative, follow-up and imaging data of the two groups were compared. [Results] All patients in both groups had ACL reconstructed successfully without a statistically significant differ- ence regarding combined meniscus injuries confirmed intraoperatively (P＞0.05), which were treated by partial meniscectomy. There were no significant differences in operation time, tendon incision length, intraoperative blood loss, postoperative ambulation time, incision heal- ing grade and postoperative hospital stay between the two groups (P＞0.05). All patients were followed up for a mean of (25.1±2.4) months, and the HT group resumed full weight-bearing activity significantly earlier than that in the QT group [(45.2±2.4) days vs (47.1±1.4) days, P＜ 0.05]. The Lysholm and IKDC2000 scores increased significantly (P＜0.05), while the side to side difference of KT-1000 test significantly reduced in both groups over time (P＜0.05). Although there were no significant differences in Lysholm and IKDC2000 scores between the two groups at any time points accordingly (P＞0.05), and no a significant difference the side to side difference of KT-1000 test between the two groups before surgery (P＜0.05), the QT group proved significantly less side to side difference of KT-1000 test than the HT group post- operatively [6 months after surgery, (2.7±0.7) mm vs (3.3±0.6) mm, P＜0.05; 12 months after surgery, (3.0±0.7) mm vs (3.6±0.6) mm, P＜ 0.05; 24 months after surgery, (3.2±0.6) mm vs (3.6±0.5) mm, P＜0.05]. Radiographically, the femoral tunnel enlargement significantly in- creased in both groups at 24 months compared with those 6 and 12 months after surgery (P＜0.05), and the QT group had significantly less femoral tunnel enlargement phenomena than the HT group 24 months postoperatively [grade 0/1/2/3: (25/18/0/0) vs (15/28/0/0), P＜0.05].[Conclusion] For arthroscopic single-bundle ACL reconstruction, the QT autograft is significantly better than HT autograft in terms of knee laxity and femoral tunnel enlargement.