To determine the clinical, angiographic and hemodynamic characteristics of patients with a strongly positive exercise test, 37 subjects demonstrating ≧ 3 mm S-T segment depression were identified among 892 consecutive diagnostic treadmill evaluations. Typical angina by history was present in 78%. 30 patients (81%) had a normal resting electrocardiogram. The strongly positive exercise response was elicited at < 90% of the predicted maximal heart rate in 31 patients (84%). 20% of patients did not experience angina during testing. 20 patients underwent cardiac catheterization. All 20 demonstrated multivessel disease and each had significant stenosis of either the left main (25%) or left anterior descending (95%) coronary artery. Left ventricular function was well preserved.