The arteriographic abnormalities found in 104 patients with typical angina pectoris and an electrocardiogram at rest which was normal at the time of arteriography were compared with those of 238 cases with typical angina pectoris, but with an abnormal electrocardiogram (127 having ST/T changes, 111 having transmural necrosis). There was no major difference between the two groups as far as the degree of coronary stenosis was concerned, nor in its extent and distribution. However, by comparison with the group with an abnormal electrocardiogram, very tight stenoses of the three trunks or of one trunk alone were slightly less common in the patients with a normal electrocardiogram; also, for each of the three trunks, the index of the lesion was slightly less raised, and the circumflex and right coronary arteries were slightly less commonly, affected, although the difference was not usually great enough to achieve significance. The action of the left ventricle and/or the value of left ventricular end-diastolic pressure were, however, manifestly better conserved in those with a normal electrocardiogram (p less than 0.001). An aorta-coronary bypass graft is more likely to be indicated in this group of patients.