By retrospective analysis of 1415 bicycle ergometer exercise stress tests, 108 patients were selected for coronary angiography and left ventriculograms at least 3 months after acute anterior wall myocardial infarction. The ECG of 55/108 showed elevation of the ST-segment of 1 mm or more during exercise. 82% displayed an aneurysm defined by diastolic and/or systolic bulge (dyskinesis) of the anterior ventricular wall: sensitivity 82%, specificity 96%, positive predictive value 97%. The bicycle exercise stress test is a strong, noninvasive predictor of left ventricular aneurysm.