The purpose of this study was to evaluate the clinical results of simultaneous arthroscopically assisted reconstruction of anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) using autogenous tendon grafts in chronic knee injuries. Nineteen patients (17 men and 2 women) with chronic multi-ligamentous injuries underwent one-stage ACL and PCL reconstruction. ACL, PCL and medial collateral ligament were reconstructed in seven knees, and ACL, PCL and posterolateral structure were reconstructed in two knees. Function of the operated knee was evaluated according to the International Knee Documentation Committee (IKDC) and Lysholm scale. Anterior and posterior knee laxity was examined with a KT-2000 arthrometer. Eighteen of 19 patients were able to return for follow-up and were evaluated objectively and subjectively. The average patient age at surgery was 30.5 years, and the average postoperative follow-up was 3.5 years. No patients showed loss of knee extension more than 5 degrees , while three patients revealed loss of knee flexion more than 16 degrees . The mean postoperative total anterior-posterior side-to-side difference was 1.9 +/- 1.5 mm at 20 degrees and 2.1 +/- 1.9 mm at 70 degrees . The average of the Lysholm score was 95.1 points at the final follow-up. At the IKDC evaluation, three patients were grade A, 11 were grade B, 3 were grade C, and 1 patient was grade D. The results showed the effectiveness and safety of one-stage reconstruction of combined ligamentous injuries of the knee that can adequately restore satisfactory stability.