Purpose : Authors investigated the associated findings and their value in the diagnosis of anterior cruciateligament(ACL) injury in MR image. Material and Methods : The knee MR images of 47 patients with ACLinjury(complete;24, partial;23) and 61 patients with normal ACL confirmed by the knee arthroscopy or operationwere reviewed retrospectively. The degree of anterior translocation of tibia and the degree of posterior cruciateligament(PCL) buckling were evaluated. The prevalence and pattern of associated adjacent bone, ligament andmeniscus injuries were studied. Results : The means($pm$2standard errors) of anterior translocation were differentsignificantly in statistical analysis(p <0.001, student t-test) between injury group(7.51$pm$1.16mm) and normalgroup(-0.56$pm$0.92mm) . In the level of 5mm of anterior translocation for the criteria of ACL injury, thesensitivity, specificity, accuracy were 78.7%, 89.5%, 84.3% for each. The means of PCL buckling ratio were alsodifferent statistically between injury group(0.23$pm$0.02) and normal group(0.17$pm$0.01)(p<0.001). In the level of0.20 for diagnostic criteria of ACL injury, the sensitivity, specificity, accuracy were 71.4%, 83.6%, 78.4% foreach. Thirty one medial meniscus tear(66%), thirteen lateral meniscus tear(28%), ten medial collateral ligamentinjury(28%), one PCL injury(2%) were associated with ACL injury. The twenty nine bone marrow changes were found intwenty patients(43%) which including acutely injured seven patients. In acute cases, the bone marrow changes weredepicted as diffuse or focal high signal intensity lesions in lateral femoral or tibial condyles in contrast tothe changes in chronic cases were depicted as focal low signal intensity lesions in variable location. Lateralfemoral condylar notch depression were found in nine patients(19%) and avulsion fractures of anterior tibial spinein four patients(9%). Conclusion : The associated findings with ACL injury (anterior translocation, buckling ofPCL, associated bone, ligament and meniscus injuries) are considered to be helpful in the diagnosis of ACL injuryon Knee MR images, when the findings of anterior cruciate ligament itself are not confirmative.