To assess the results of thrombolytic therapy and surgical decompression of the thoracic outlet in the management of spontaneous axillary vein thrombosis (AVT), the records of 38 patients at New York University Medical Center (NYUMC) with AVT were reviewed. Excluded from this report were 20 patients who had AVT secondary to an underlying medical condition, a subclavian catheter, or a failed dialysis access graft. Of the 18 remaining patients with no underlying medical condition, all were found to have effort-related axillo-subclavian thrombosis, Paget-Schroetter syndrome. Urokinase was used for thrombolysis in 17 of the 18 patients, (94.4%) with complete lysis in 14 (82.4%). The remaining patient received anticoagulation only following a favorable response to an initial heparin infusion. Of the patients achieving complete thrombolysis, all but one received urokinase within 8 days of the onset of symptoms. Clot lysis revealed axillary vein compression secondary to a thoracic outlet syndrome in 11 patients, and these underwent staged transaxillary thoracic outlet decompression by first rib resection. All 17 patients have been followed for a mean of 21 months, and none receiving lytic therapy have reoccluded. Review of these data confirms earlier reports showing that with early diagnosis, thrombolysis and, if indicated, thoracic outlet decompression, patients with spontaneous AVT can expect excellent clinical results with a good long-term prognosis.