Sequential angiographic follow-up is needed for interpretating coronary events that occur after successful percutaneous translumial coronary angioplasty (PTCA). One hundred eight consecutive patients who had undergone successful dilatation were followed for 10 years, and quantitative sequential angiograms were recorded at 6 months (n = 101) and 10 years (n = 68). The 10-year event rate was: 5.8 ± 2.4% for cardiac death, 9.7 ± 3.3.% for Q-wave acute myocardial infarction, 18.3 ± 4.5% for additional surgery, and 22.4 ± 4.9% for repeated angioplasty. Using Cox’s proportional-hazards regression, multivessel coronary artery disease (CAD) (RR 5.6; 95% confidence intervals CI 1.2 to 24.7; p = 0.02), restenosis within 6 months (RR 7.8; 95% CI 3.1 to 20.0; p = 0.0001), and CAD progression over 10 years (RR 10.6; 95% CI 1.3 to 87.1; p = 0.004) were the strongest predictors of all-cause death, repeated PTCA, and additional surgery, respectively, after controlling for age and coronary risk factors. The minimal luminal diameter of 48 narrowings with complete sequential angiographic follow-up and without restenosis remained stable from 6 months (2.13 ± 0.60 mm) to 10 years (2.18 ± 0.61 mm). Disease progression was similar in nondilated arteries and dilated arteries (32% vs 30%). The 10-year risk of coronary events was higher in patients with baseline multivessel CAD than in those with 1-vessel CAD because of more frequent progression of CAD (RR 3.8; 95% CI 1.6 to 6.8; p = 0.001). Thus, early cardiac events after successful PTCA were related to restenosis, and late events to CAD progression. Nevertheless, after the restenosis period, the target lesion remained stable for the next 10 years. Coronary disease progression was not related to the angioplasty procedure.