The results of percutaneous transluminal coronary angioplasty were studied in 1352 consecutive patients. The angioplasty procedure was angiographically successful in 1163 (86%) patients and the success rate increased gradually with time. There were no significant differences in success rates in different vessels or indications. The success rate for repeat coronary angioplasty was 92%. In 85% of the patients the clinical course was uncomplicated. Myocardial infarction occurred in 3.6%, emergency coronary bypass grafting in 2.6%, elective bypass surgery in 4.6%, and there were 10 deaths (0.7%). There were 16 deaths (10 non-cardiac) during follow up in the 1163 patients in whom the first procedure was successful. Actuarial analysis showed that after a first angioplasty 77.9% remained free of symptoms and cardiac events for five years and that after a second angioplasty 76% did so. Angiographic follow up showed restenosis in 24% of patients but the overall clinical success rate was 86.2%. On the basis of the intention to treat the procedure was successful in 74.3% of all 1352 patients. Coronary artery bypass surgery was eventually performed in 11.6% of all patients. The long term angiographic success rate of coronary angioplasty is higher than previously suggested.