In a relatively small personal series (41 patients) of first rib resections for thoracic outlet compression, I have encountered 8 patients in whom venous obstruction at the thoracic outlet was the major component. Four of the 8 had typical "stress" thrombosis of the axillary vein. Angiography demonstrated a tight thoracic outlet to be the underlying cause of the venous thrombosis. In the 4 patients with venous compression but without thrombosis, angiograms suggested that each was a candidate for axillary venous thrombosis unless the underlying thoracic outlet compression syndrome was relieved. Although thoracic outlet compression has been documented as a cause of "stress thrombosis" of the axillary vein, the relationship of the two conditions apparently is often overlooked, even by experienced thoracic surgeons. Representative case histories and angiograms are presented to demonstrate the close relationship of thoracic outlet compression and axillary venous thrombosis.