Sudden cardiac deaths are common within the community. They also constitute a substantial part of daily pathologic and forensic case work. However, macroscopic myocardial findings indicating acute ischemia are often absent. Then, diagnosis is based on coronary status in combination with indirect signs of acute cardiac failure. We present a case of sudden cardiac death where diagnosis was based on cardiac postmortem magnetic resonance imaging (pmMRI) findings already prior to autopsy: the heart's anterior basal ventricular septum showed hypointensities in T2-weighted images that raised suspicion of peracute ischemia. The lumen of the left anterior descending artery (LAD) exhibited a lack of otherwise discernible postmortem sedimentation of cellular blood components. Instead of a sharp border between serum and erythrocytes a homogeneous signal was seen within the narrowed lumen of the beginning LAD over a length of 1cm. Based on this, a thrombotic occlusion was assumed. Subsequent autopsy confirmed peracute septal myocardial ischemia secondary to a thrombotic occlusion of the LAD as concluded from the pmMRI.