The clinical and hemodynamic results of 87 patients (average age 49 years, range 22 to 65 years) with left ventricular aneurysm were retrospectively investigated before and after (1-87 months) surgical treatment. 34 patients underwent aneurysmectomy only (group 1), 35 patients additionally underwent coronary revascularisation (group II), and 18 patients underwent--because of findings during operation--coronary revascularisation only (group III). The size of aneurysm was not significantly different in the three groups. Postoperatively it decreased only in groups I and II. The majority of the patients in group I (with predomination of one-vessel disease) had no angina pectoris. There was no significant change early and late (more than 12 months) after the operation. The patients in groups II and III (the majority with multi-vessel disease) showed an improvement of angina pectoris. Preoperatively most of all the patients claimed to have exertional dyspnea. On the whole, there was no significant change after operation. The majority of the patients showed an improvement in their angina pectoris and dyspnea when those symptoms were the major indications for the operation. Heart rate, systolic and end-diastolic pressure in the three groups did not significantly change after the operation. End-diastolic and end-systolic volumes decreased significantly in groups I and II. The ejection fraction increased significantly. In group III these parameters did not change. Circumferential fiber shortening velocity in the residual ventricle significantly increased only in group I. Hemodynamic studies during exercise were performed in total on 32 patients. In group I, there was a significant smaller increase of the mean pulmonary artery pressure, no significant change in groups II and III. At rest, only the patients with aneurysmectomy showed an improvement of the global and residual left ventricular function. The patients with an angiographically presumed aneurysm and viable myocardium found intraoperatively showed no improvement in function at rest or during exercise even after coronary revascularisation. The hospital mortality was 6%. Three patients died during the follow-up period because of ascertained cardiac reasons. The high mortality of non-operated patients with similar clinical and hemodynamic findings as in operated patients warrants an indication for aneurysmectomy without even taking into account the symptomatic and functional improvements.