In the 4 years from June 1983 to July 1987, PTCA was performed in 104 patients with coronary artery disease at Severance Hospital, Fifty-seven of 61 patients after successful PTCA in non infarct-related artery, underwent follow-up from 1 to 42 months (mean 11 months) after successful PTCA. Degree of stenosis before PTCA was 83.1+/-9.8% and after 30.2+/-10.9%, Twenty-four of them was performed followed coronary angiogram, and so reangiography rate was 42.1%. The symptomatic recurrence rate after first PTCA was 49.1% (n=28). Angiographic restenosisi rate after first PTCA was 28.1%(n=16). Sixteen(88.9%) of 18 patients who was performed follow-up reangiogram due to symptomatic recurrence showed angiographic retenosis. Patients who received successful second angioplasty due to restenosis (n=11), had a symptomatic recurrence rate of 63.6%(n=7). all symptomatic recurrences developed within 1 to 4 months (mean 50.9+/-21.5 days)after PTCA. Despite uneven attempt rates in patients undergoing PTCA to the left anterior descending artery (LAD), right coronary artery(RCA) and left circumflex, restenosis rates wer 28% (13/47) in LAD and 10% (1/10) in RCA after first PTCA. Two of the patients with second retenosis after repeat PTCA had taken 3rd PTCA, one of them had a symptomatic recurrence within 1 month after 3rd PTCA. PTCA is an effective and relatively safe therapeutic procedure in selected patients with coronary artery disease, but restenosis after PTCA is a critical factor limiting the overall usefullness.