A totally implanted subclavian venous access system composed of a reservoir and silastic catheter was employed in 92 patients receiving infusion chemotherapy and/or hyperalimentation. The major catheter complication was subclavian or jugular vein thrombosis observed in 15 patients (16%). Thrombosis was observed in the ipsilateral subclavian or jugular vein surrounding the catheter without restricting function, except in two patients with thrombosis in the vein at the end of the catheter. Prophylaxis with low-dose Coumadin was effective in preventing thrombosis in high-risk patients as defined by a history of prior thrombosis. Streptokinase and/or heparin relieved the signs and symptoms of thrombosis, but clot dissolution or reversal of collateral flow was not observed. Explantation of the catheter was not necessary in all patients in that embolic complications of the thrombosis were not observed, and the system was retained and functioned in five patients in spite of the presence of thrombosis around the catheter. Other complications of the implanted system include "pocket" infection, catheter migration, and occlusion. Most complications may be managed without obligate catheter removal.