Systemic thrombolysis is less than optimal in total occlusions of the iliac vein in which patency is 20% or less. We describe an interventional therapeutic procedure that may be effective in such cases. We selected 18 patients (average age, 29.5 years; range, 16 to 71 years) with complete iliac vein occlusion that persisted after 24 to 48 hours of systemic thrombolysis (streptokinase 100,000 U/hr). The ipsilateral femoral vein was punctured, and a guide wire was gently advanced through the thrombus into the inferior vena cava. Multiple inflations were performed with a balloon catheter that was advanced on the wire. A temporary vena cava filter was placed as a protection against possible embolic migration. Systemic thrombolysis was administered for 24 to 48 hours. Control venography and pulmonary angiography were performed. Venography showed good recanalization in seven cases, incomplete recanalization in five cases, and failure in six cases. Patency was maintained for a long time (15.6 months). In conclusion, (1) percutaneous transluminal venous angioplasty is a valuable adjunct to systemic thrombolysis when the latter alone fails; (2) segmental flow and mechanical obstruction were the critical factors, since the pharmaceutical factors were held constant, and (3) a more aggressive incremental interventional strategy warrants consideration.