At the Department of Paediatric Surgery of the University of Zürich, severe distorsions with ruptures of the lateral ligaments of the ankle were operated upon since 1975. The indication for surgical repair was a subluxation of the talus in the antero-posterior x-ray of more than 10 degrees compared with the opposite side during the classical manoeuvre of supination of the forefoot. The late results of 46 of the 55 patients, aged 4 to 15 years, are presented 1 to 5 years after surgery. 33 (71.7%) were completely free of symptoms and very active in sports. 9 (19.6%) had occasionally slight complaints, especially during changes of weather etc. 4 (8.7%) complained about severe pain around the ankle and had about one painful distorsion a week. The x-ray control showed an excellent stability of the lateral ligament in 91.3%. Only 4 patients (8.7%) had a subluxation of the talus over 10 degrees. The 4 patients with severe pain were transferred to an orthopaedic surgeon for an active stabilisation procedure. Our operative results are by far better than other series with conservative treatment. We think, therefore, that severe ruptures of the ankle should be treated surgically.