We investigated the diagnostic value of arthrography in ankle sprains. In the 57 patients operated upon, arthrographic findings were compared with surgical findings. Extracapsular contrast medium leakage in an arthrogram performed within 3 days from the injury, showed a reliabily of 100% in predicting ligamentous rupture. Peroneal sheath and subtalar joint communication were of value in the diagnosis of calcaneofibular ligament rupture. Sinus tarsi leakage and anterior subtalar Joint communication, which were not previously reported, were thought to correlate to subtalar sprains.