Ninety-nine patients underwent embolectomy of upper extremity arteries; in 12% of the cases reoperation and in 4% amputation was necessary. Thrombosis is the cause of reocclusion of the brachial artery, based on endothelial lesions of the axillary passing into the brachial artery. At autopsy studies these andothelial lesions were verified by histological and electron-microscopical examinations in a high percentage. Therefore embolectomies should be performed very carefully by means of thin fogarty catheters. Postoperative anticoagulant therapy seems to improve the survival rate.