A comparative study is presented of seventy-nine patients with rupture of the tendo achillis, forty-eight of whom were treated surgically and thirty-one, non-surgically. With one exception, all were healthy, athletic individuals. Twenty-two per cent of the patients had an initial misdiagnosis. The patients treated surgically were more satisfied with the results of their treatment. Strength, power, and endurance as measured on the Cybex II dynamometer revealed that the patients treated non-surgically attained only 72 per cent of normal strength and 70 per cent of normal power and endurance as compared with the surgically treated patients. Wound complications occurred in only two patients and no reruptures occurred in the surgically treated group, whereas there were nine rereptures in the group not treated surgically.