Two hundred and seventeen consecutive patients with two hundred and twenty five diaphyseal tibia fractures were retrospectively reviewed to evaluate the frequencies, types and the results of treatments for the associated ipsilateral knee ligaments and menisci injuries from May 1993 to Feb 1997 at Eulji Medical College Hospital. Average follow-up period was 41 months(20~65 months). Thirteen patients with knee injuries(5.8%) were diagnosed by stress X-ray & MRI evaluation and confirmed by arthroscopic examination. Eleven patients(84.6%) were diagnosed as having a ligament or meniscus injury at the time of initial management. The posterior cruciate ligament(PCL) was injured in eight patients(50%); the anterior cruciate ligament(ACL), in three; the medial collateral ligament, in three; the lateral collateral ligament, in two: the medial meniscus, in two; and the lateral meniscus, in two. There was no relationship between specific ligament damage and the cause of the injury or level of fracture. Collateral ligament injuries, two ACL, and four PCL injuries were treated conservatively and one PCL injuries were treated with pull-out suture technique and another four PCL injuries were treated with reconstruction using bone-patella tendon-bone. One ACL injury was treated with reconstruction using semitendinosus tendon. As evaluated by the method of HSS knee score, there were seven(53.9%) excellent, four(30.8%) good, and two fair(15.3%). On the basis of the results of this study, we believe that, after stabilization of a fracture of the tibial shaft, it is essential to examine the knee throughly to identify any associated ligamentous injuries.