Objectives: To determine the angiographic appearance of the dilated coronary artery and the cause of symptoms in patients who presented with a return of chest pain more than 1 year after successful percutaneous transluminal coronary angioplasty (PTCA). Design: Retrospective analysis of coronary angiograms and review of case histories. Patients and methods: 112 patients who underwent repeat coronary arteriography for investigation of chest pain 13-105 (median, 30) months after successful coronary angioplasty were studied. All patients were free of symptoms for at least 12 months after the initial angioplasty. Results: A return of chest pain was attributed to restenosis in 12 patients (11%), to a new lesion or worsening of pre-existing coronary lesion in 56 patients (50%), and to both restenosis and stenosis in non-dilated coronary segments in 10 patients (9%). There was no restenosis in 112 of the 134 dilated lesions (84%). In 34 patients (30%), there was no significant stenosis in either dilated or non-dilated coronary segments. Conclusions. In patients undergoing coronary angiography for the investigation of recurrent chest pain more than 1 year after successful coronary angioplasty, the majority of dilated coronary segments had a good angiographic appearance. Late onset angina following PTCA is usually due to new coronary lesions or worsening of pre-existing mild stenosis.