Objective To evaluate the primary cl inical results of double-bundle anterior cruciate l igament reconstruction (ACLR) with semitendinosus allografts. Methods From March 2006 to October 2006, 33 patients underwent double-bundle ACLR with semitendinosus allografts. The complete followed-up data of 31 patients was analyzed retrospectively. There were 24 males and 7 females aged 18-35 years old (average 25 years old). The injury was caused by sports accidents in 23cases and traffic accidents in 8 cases, involving the left knee in 18 cases and the right knee in 13 cases. Anterior cruciate l igament rupture were confirmed by MRI and arthroscopy in all the patients, without lateral collateral l igaments injuries and posterior cruciate l igament injuries. The time from injury to operation was 1-43 months (average 11 months). The knee was fixed at 0° position after operation for 2 weeks and got knee joint rehabil itation exercises gradually. Results The incision of 2 patients showed effusion 4 and 7 days after operation, respectively, and healed after symptomatic treatment. The incision of 29 patients healed by first intention. There were no compl ications such as stiffness of knee joint, neurovascular injuries and joint infections. All the patients were followed up for 24-29 months (average 26 months). MRI displayed the anterior cruciate l igament grafts presented with good connection and signal similar to the normal 2 years after operation. There was significant difference between the preoperational value and the final follow-up value in terms of bilateral knee joint difference of prior laxity, Lachman test, and pivot shift test (P lt; 0.05 ). The circumference difference between the injured and the normal was (11.6 ± 7.9) mm before operation and (5.0 ± 3.1) mm at the final follow-up (P lt; 0.05). The Tegner score, Lysholm score, and International Knee Documentation Committee score was 3.83 ± 1.15, 64.38 ± 6.81, and 41.42 ± 6.30, respectively, before operation, and 6.29 ± 0.64, 94.45 ± 3.03, and 95.72 ± 3.10, respectively, at the final follow-up. There was a significant difference between before and after operation (P lt; 0.05). Conclusion The primary cl inical results of double-bundle ACLR with semitendinosus allografts are satisfactory and the allogeneic semitendinosus are good grafts for double-bundle ACLR.