Immediate effect of PTCA and CABG for unstable angina then followed-up for PTCA and CABG several years are analyzed in 112 patients selected out of 204 unstable angina patients hospitalized from 1990 to 1991. Fifty three patients, aged 25-68 (mean 51) were assigned to PTCA, fifty nine aged 33-69 (mean 53) were subjected to CABG. Both groups comprised of 72% and 83% males respectively. Nine patients with de novo angina, forty with crescendo angina and four with prolonged stenocardia were assigned to PTCA. 28% of patients have had myocardial infarction. Nine patients with de novo angina and fifty with crescendo angina were assigned to CABG. 56% of them have had myocardial infarction. Left ventricular ejection fraction (LVEF) less than 40% was found in 8 (15%) PTCA patients and in 18 (31%) patients who underwent CABG. Full revascularization was achieved in 38 (73%) patients treated with PTCA and 46 (78%) CABG patients. In 9/17% patients only critical stenosis in multivessel disease was subjected to PTCA. Four cases of myocardial infarction underwent intervention and all of these patients died: one (2%) after PTCA, and three (5%) after CABG. Fifty two patients after PTCA and fifty six after CABG were followed for one to four (mean 3) years. Thirty one percent of patients after PTCA and 41% after CABG were asymptomatic, 61% and 54% respectively had little to moderate symptoms. Left ventricular systolic function improved in most patients, predominantly in those with LVEF less than 40% (p < 0.05) treated with PTCA. Hospitalization due to anginal pain was needed in 46% of patients after PTCA and 15% after CABG (p < 0.05). Coronary artery restenosis after PTCA was successfully treated with re-PTCA or CABG in 9 (17%) patients. Venous graft stenoses were dilated in two cases. Myocardial infarction occurred in 3 (6%) patients after PTCA and 2 (4%) patients after CABG. One patient died after redilatation CABG treated patients required nonsignificantly less antianginal drugs. Four week survival rate in PTCA group and CABG group was 98% and 95% respectively; three year survival was 95% in both groups. We conclude, that unstable angina patients requiring either angioplasty or surgery may expect good procedural and long term prognosis. Remarkably good results may be expected in successfully revascularised patients with low ejection fraction.