Seven patients with typical variant angina without coronary stenoses greater than 50% developed angina and ST-segment elevation during treadmill exercise testing. In all cases the ST-segment elevation occurred in the same leads during exercise testing as during spontaneous attacks at rest. Five of the patients had developed spontaneous coronary spasm during coronary arteriography, in each case in the artery corresponding to the site of ST-segment elevation. In five patients, thallium was injected during the exercise test during which angina and ST-segment elevation occurred. In each case, a large perfusion defect not present at rest was found in the zone corresponding to the site of ST-segment elevation. These findings suggest that coronary artery spasm may occur during exercise in patients with variant angina.