From January 1987 to January 1992, 11 patients underwent percutaneous transluminal angioplasty (PTA) for the treatment of subclavian artery stenosis before or after coronary artery bypass grafting (CABG) using the internal mammary artery (IMA). There were 8 men and 3 women, with a mean age of 57 +/- 7 years. Four patients had PTA 1 to 4 months before undergoing CABG with IMA grafts, because of either asymptomatic supraclavicular murmurs or neurologic symptoms. Seven patients underwent PTA 2 to 37 months after CABG with IMA grafts, because of recurrent angina. Subclavian artery stenosis was on the left side in 9 patients, the right side in 1 patient, and bilateral in 1 patient. Ten PTA procedures were successful in 9 patients. All patients with post-CABG angina had reversal of the ischemia. There were three complications: one femoral artery thrombosis, one brachial plexus hematoma after an axillary approach, and one acute pulmonary edema after the procedure. Follow-up after PTA ranged from 1 to 60 months (mean, 38 +/- 17 months). Nine patients had no angina at follow-up and 2 had stable angina (class II) upon exertion. Upper-limb Doppler studies showed no evidence of restenosis in any of these patients at a mean follow-up of 38 months. Subclavian artery PTA is a useful alternative to IMA bypass grafting in patients with subclavian artery stenosis discovered preoperatively, and it is the treatment of choice for those presenting with post-CABG angina due to subclavian artery stenosis proximal to an IMA graft.