The purpose of this investigation was to compare data on early exercise testing for variables known to be of diagnostic/prognostic value following myocardial infarction in post-myocardial revascularization surgery patients. 70 patients were evaluated soon after surgery, by cardiac catheterization, moderate-intensity treadmill exercise testing, and rest and exercise radionuclide angiography. The results indicated no significant differences among groups with satisfactory and unsatisfactory results by catheterization compared for METs, peak heart rate, double product, ST-segment change, angina pectoris, and dysrhythmias. Significant differences were found among groups when rest and exercise ejection fraction and exercise-induced regional wall motion abnormality were taken into account. It was concluded that the moderate-intensity treadmill exercise test was ineffective in differentiating current cardiac function and arterial/graft status among postmyocardial revascularization surgery patients. Exercise radionuclide angiographyc studies were able to identify groups of patients with adequate or inadequate postoperative cardiac catheterization results.