In a six-year period (1982-1987), 248 patients were treated with 297 procedures (percutaneous transluminal coronary angioplasty, PTCA) on 282 vessels. Two hundred and fifty-nine (87.2%) of the procedures in 210 (76.7%) of the patients appeared successful angiographically. Thirty-eight procedures were unsuccessful due to failure to pass the stenosis in 18 patients, dissection or occlusion of the treated vessel in 11, and significant residual stenosis in 9 patients. Emergency operations were performed after 11 (3.7%) of the procedures. Two patients died postoperatively. Myocardial infarction was seen in 13 patients, of whom 4 developed pathologic Q-waves in their ECG. Restenosis occurred in 60 (28.6%) of the patients. In the last year of the study, the patients selected for PTCA were in a poorer state angiographically, but the results of PTCA were better, without any increase of the complication rate. Our results, which are in accordance with others, support the concept that PTCA is a relatively safe procedure with a primary success rate of almost 90 percent. However, approximately one third of the patients developed restenosis, which in most cases occurred within 3 months.