Anterior and inversion stress were applied to the lateral ligaments of the ankle and the findings compared with the arthrograms. Fifty-five patients underwent stress radiography of both ankles and arthrography of the injured ankle within 72 hours of acute injury to the lateral ligaments. Ten patients had normal arthrograms and 45 had evidence of ligamentous injury. Anterior stress measurements could not be correlated with arthrography, and no differentiation between single and double ligament tears could be made. Inversion stress testing was very accurate in predicting ligamentous injury when the angle of inversion was 10 degrees or greater but achieved this degree of accuracy in only 38.2% of patients.