PURPOSE: To evaluate the diagnostic accuracy of MR imaging in posterior cruciate ligament(PCL) injuries, to describe the variety of these injuries and to assess the type and frequency of associated knee injuries. MATERIALS AND METHODS: We retrospetively analysed 75 cases with knee injuries. In all cases, the prescence of a PCL tear was determined by arthroscopy or surgery and the type of tear and patterns of associated knee injuries were described. RESULTS: Twenty-eight PCL tears were identified with arthroscopy or surgery. Figures for the sensitivity, specificity, and accuracy of MR diagnosis for the PCL injury were 86%, 94% and 91% respectively. Twenty-one cases(75%) had complete PCL tears and seven (25%) had partial tears. The commonest tear site was midsubstance(18 cases, 64.3%). Twenty-seven cases(96%) had associated knee injuries ; the remaining patient(4%) had isolated PCL injuries. There were 19 cases(68%) of ligamentous injuries, ten (36%) of meniscal tear, ten (36%)of bony injuries, and 20 (71%) of joint effusions. Of the ligamentous injuries, those involving the medialcollateral ligament were most often seen(10 cases, 36%). CONCLUSIONS: MR imaging is an accurate method for the detection and evaluation of PCL injury and associated knee abnormalities.