To establish whether re-occlusion of the femoral artery could be prevented, in 6 consecutive patients undergoing percutaneous transluminal angioplasty (PTA) for superficial femoral artery occlusion the recanalised segment was isolated, with a 7-French double-balloon catheter. 5 mg recombined human tissue-type plasminogen activator (rt-PA) and 1000 IU heparin were then infused into the enclosed space for 30 minutes, followed by intravenous heparin for 24 hours. At 10 and 30 days all 6 patients had evidence of recanalisation and remission of symptoms. Mean ankle-arm pressure index improved by 72% at 24 hours, by 118% at 10 days, and by 103% at 30 days after the procedure. No patients had major complications. Treatment of superficial femoral artery occlusions by PTA with rt-PA and intravenous heparin seems to prevent rethrombosis.