The potential of ungated computed tomography (CT) to detect and quantify myocardial infarctions was assessed in 10 dogs. Twenty-seven in vivo CT examinations were performed at various time intervals (1 hr-20 days) after coronary artery occlusion. After intravenous contrast administration, CT delineated the infarcted myocardium in all 27 studies. The CT-determined infarct volume before sacrifice was closely correlated (r = 0.98) with the postmortem infarct weight. Delayed accumulation of iodinated contrast material in the infarct was seen in all 22 examinations performed 3 1/2 hr or longer postocclusion. The dynamics of contrast material accumulation and disappearance from normal and ischemic myocardium were also assessed. Presently available CT scanning without gating can noninvasively detect and quantify myocardial infarctions of various sizes and ages in living animals and can evaluate contrast dynamics whose time course is greater than a single circulation time.