Nonsignificant coronary artery plaque rupture or erosion may be the origin of acute myocardial infarction (AMI). The aim of our study was to assess the ability of multislice computed tomography (MSCT) to detect coronary plaques responsible for near normal coronary angiography AMI. Eight patients with presentation of AMI and no significant coronary narrowing by angiography were enrolled. Two groups were defined: (1) true AMI and (2) myocarditis. MSCT was able to detect nonsignificant coronary soft plaques responsible for AMI and has provided information on plaque volume, eccentricity, and density. In patients with myocarditis, there was no evidence of plaque.