Purpose : To compare the functional evaluation with the posterior translation after arthroscopic PCL reconstruction in isolated and combined PCL-deficient knees. Materials and Methods : We retrospectively evaluated 45 patients with PCL-deficient knees who were treated by arthroscopic PCL reconstruction using Achilles tendon allograft from June 1994 to June 2000. The differences of posterior translation were measured with posterior stress lateral radiographs and KT-2000 arthrometer. The functional results were evaluated using the Lysholm knee score and IKDC evaluation form. Results : Preoperative mean side to side differences of the posterior translation were 11.83 mm in isolated PCL-deficient knees and 12.7 mm in combined PCL-deficient knees respectively. At the last follow-up in isolated and combined PCL-deficient knees, the mean radiographic side to side differences of the posterior translation were 6.38 mm and 6.7 mm, the average corrected 20 Ib posterior displacements using KT-2000 arthrometer were 3.5 mm and 4.1 mm, the mean Lysholm score were 87.4 and 81.2, the grade A and B of IKDC evaluation form were 16 cases $(88.9\%)$ and 23 cases $(85.2\%)$, respectively. Conclusion : The functional results had no relationship with the degree of posterior translation after arthroscopic PCL reconstruction. Tendency of posterior translation may be influenced by associated injury of the knee.