We examined 100 patients with the TOS treated surgically. One hundred and twenty first ribs were resected using the transaxillary approach. Ninety per cent good and excellent results were obtained. EMGs and conduction studies through the outlet are of little value. Many of our patients presented with a double crush syndrome. Trauma was a significant antecedent in 44 per cent of our patients. The diagnosis of TOS depends on a careful clinical evaluation. There are no laboratory tests, x-rays, electrical studies, or infallible clinical tests to establish the diagnosis. There will always be some errors in diagnosis, and surgery must be advised on a basis of exclusion and with great reservation.