Of the 1,213 clinical cases of lateral tennis elbow seen during the time period from December 19, 1971, to October 31, 1977, eighty-eight elbows in eighty-two patients had operative treatment. The lesion that was consistently identified at surgery was immature fibroblastic and vascular infiltration of the origin of the extensor carpi radialis brevis. A specific surgical technique was employed, including exposure of the extensor carpi radialis brevis, excision of the identified lesion, and repair. The results at follow-up were rated as excellent in sixty-six elbows, good in nine, fair in eleven, and failed in two. There was an over-all improvement rate of 97.7 per cent, and 85.2 per cent of the patients returned to full activity including rigorous sports.