20 patients with acute traumatic rupture of the anterior talofibular ligament and ligamental suture were studied postoperatively by MRI. MR results were correlated with stress x-ray studies. We found a normal anterior talofibular ligament in eight cases. However, stress x-ray images showed normal stability of the ankle joint in eighteen cases. In six patients the anterior talofibular ligament was thickened, in another six cases it could not be separated from scar tissue. Therefore MR imaging of ankle ligaments did not allow a diagnosis of their function. Nevertheless, sequelae of the ankle trauma such as osteochondrosis, exudation into the ankle joint and tendovaginitis of the flexor muscles were sensitively visualised by MR.