Purpose: To analyze the clinical results and second look arthroscopic findings of anterior cruciate ligament(ACL) reconstruction with a tibialis anterior tendon allograft and a hamstring tendon autograft. Materials and Methods: We reviewed the cases of athroscopic ACL reconstructions using allogenous tibialis anterior(TA) tendon and autogenous hamstring tendon done from March, 2002 to August, 2005 and followed-up more than 1 year. The 250 cases were included in this study and allogenous TA tendon was used in 150 cases and autogenous hamstring tendon in 100 cases. The mean follow-up period was 15 months and 14 months, respectively. The clinical evaluation was done by Lachman test, Pivot shift test, KT-1000 arthrometer and International Knee Documentation Committee(IKDC) knee score. Graft tension, synovial coverage were observed in cases of second look arthroscopy. Results: At final follow-up, there was no significance between the two groups in clinical examination. On second look arthroscopy, synovial coverage was better in autogenous hamstring tendon group than allogenous TA tendon group(p=0.005). But no difference was found in graft tension(p>0.05). Conclusion: There were no significant differences between the two groups in the clinical results. But autogenous hamstring tendon group had better synovial coverage than allogenous TA tendon group in second look arthroscopy.