The object of the present investigation was to attempt to assess the value of some selected individual aspect of the clinical examination of patients with acute ankle injuries with tenderness, swelling or haematoma in the neighbourhood of the lateral malleolus. An attempt was made to investigate whether it was possible to differentiate the group of patients in whom radiographic examination of the ankle was necessary and whether this could be done with sufficient certainty on the basis of the clinical parameters examined. The results are presented in the form of calculation of the diagnostic frequencies. Absence of tenderness over the posterolateral edge of the lateral malleolus was found to be the clinical finding which could be employed to exclude fracture with greatest certainty, as the true negative diagnostic frequency was found to be 97.33 (90.70-99.68). This certainty is of the same magnitude as the certainty of previously selected criteria but the examination appears to be simpler and more objective.