One hundred and five consecutive patients with a closed acute rupture of the tendo achillis were assigned randomly for surgical or non-surgical treatment. After treatment, the patients were evaluated clinically and with static and dynamic measurements of plantar flexion strength. Only minor differences were noted between the final results in the two groups. Non-surgical treatment had the advantages of shorter morbidity and no hospital stay. The frequency of major complications was about the same in both groups of patients: two re-ruptures and two deep infections in patients who had operations as compared with five re-ruptures in the conservatively treated patients. I concluded that non-surgical treatment offers advantages over surgical treatment.