The correlation between the presence of areas of jeopardized myocardium and the electrocardiographic patterns of anterior and inferior Q-wave and non-Q-wave infarctions was studied in 486 patients who had had stable symptoms for at least six months after a single myocardial infarction. Myocardial jeopardy was identified on a ventriculogram in the right anterior oblique position if normal or hypokinetic wall motion was seen in all segments distal to a lesion that caused stenosis of greater than 50% and less than 100% in the proximal or mid left anterior descending coronary artery (anterior jeopardy), or in the proximal or mid right coronary artery or proximal circumflex coronary artery in a left dominant circulation (inferior jeopardy). Patients with non-Q-wave anterior infarctions had a significant increase in the frequency of jeopardized myocardium when compared with patients with Q-wave inferior or anterior infarctions. The group with non-Q-wave anterior infarction also had a significantly lower percentage of myocardial segments with absent wall motion in the area of infarction than all other groups. This combination of coronary narrowing with retained wall motion may contribute to the increased frequency of reinfarction seen in some studies of non-Q-wave infarction.