The authors described the usefulness of magnetic resonance imaging in the evaluation of the viability of the left ventricular myocardium in a patient with a history of cardiac infarction treated with primary coronary angioplasty (primary PCI) and with symptoms of postreperfusion injury of the left ventricular muscle (no-reflow phenomenon). The perfusion of the left ventricular myocardium was evaluated with the use of paramagnetic contrast. The heart movement was evaluated at rest and after the administration of a small dose of dobutamine. The use of magnetic resonance tomography made it possible to pinpoint the area of stunned and necrotic myocardium.