A procedure has been devised for treatment of the inability to extend the elbow due to either a fixed contracture of the flexor muscles or increased involuntary flexor-muscle tone and spasticity. The operation consists of lengthening all of the primary elbow-flexor muscles. It has been used successfully in thirty-two elbows of twenty-six children with cerebral palsy who were followed for an average of four years (range, two through six years). The average gain in extension was 40 degrees, and there was no loss of the patient's ability to flex the elbow or supinate the forearm. No vascular or neural complications were encountered. Independence in feeding was achieved in four patients. Seven patient acquired the ability to engage in sports and six, who previously had been unable to walk independently due to inability to handle crutches, could do so following this procedure.