This study was conducted to determine the long-term effects of percutaneous transluminal coronary angioplasty (PTCA) on the incidence of myocardial infarction, survival, and relief of symptoms. A total of 124 patients were included in the study and were followed for 16 to 25 months. The success rate of PTCA was 91.2% and 160 stenoses were dilated. Fifty-nine patients had multivessel disease (MVD) and 54 had single-vessel disease (SVD). There was no difference in survival when patients with SVD were compared with those with MVD. The cardiac survival rate for both groups was greater than 98%. Nine patients had myocardial infarction in the area of the dilated artery: 3 patients (5.5%) with SVD and 6 patients (10.1%) with MVD. Ninety-six patients (84.9%) remained free of symptoms: 46 patients (85.2%) with SVD and 50 patients (84.7%) with MVD. These data demonstrate the long-term efficacy of PTCA in patients with SVD and MVD with regard to control of symptom of angina, improved survival, and prevention of myocardial infarction.