The purpose of this study was to evaluate the results of operative treatment of entrapment of the sciatic nerve by tight fibrous structures associated with the hamstring tendons close to their proximal insertion. We retrospectively evaluated the results of 22 operations performed in 16 patients (6 bilateral operations), on average six years postoperatively. There was complete relief in 11 cases, good relief in 8 cases and fair relief in 3 cases. Entrapment of the proximal sciatic nerve by the hamstring tendons is not presented in standard textbooks. However, this condition is not extremely rare. A wide range of material has been published on operative treatment of the hamstring syndrome, but the patients were essentially active athletes. Our material consisted of ordinary patients who were referred to the university central hospital for orthopaedic consultation. The results of surgical treatment of hamstring syndrome are very encouraging.