It is generally accepted that posterior cruciate ligament is the prime stabilizer and perhaps the most importent ligament in the knee. We agreed that primary repair or reconstruction of ruptured posterior cruciate ligament is essential. Recently Clancy reported good results to correct knee instability due to rupture of the posterior cruciate ligament with a procedure that employes a free graft of one-third of the patella tendon with its tibial and patella attachments. The free patella tendon graft has been shown to revascularize readly, develop resonably high tensile strengh, allow bone to bone healing, have excellent static stability and not to deprive the knee of a significant stabilizer. So, we analized the 10 cases of the posterior cruciate ligament injuries who were admitted and treated reconstruction using free patella tendon graft in Busan Paik Hospital between May, 1984 to Dec, 1986 and obtained the following results. 1. In 8 cases, obtained satisfactory results. In 2 cases, obtained unsatisfactory results due to combined other compartment injuries, but improved posterior stability than preoperative status. 2. Reconstruction of posterior crucitae ligament using free patella tendon graft was excellent procedure for regaining of static stability of the knee.