Synovial osteochondromatosis in the knee joint is rarely a confusing diagnostic problem. Diagnosis depends on the clinical circumstances of the case and a radiologic interpretation which can exclude soft tissue tumors with calcifications and other malignant tumors characterized by the presence of multiple osteo-cartilaginous bodies. The relative value of computed tomography (CT) in the diagnosis of synovial osteochondromatosis is emphasized and the differential diagnosis discussed.