Two cases of cardiomyopathy were studied by echocardiography, endomyocardial biopsy carried out during cardiac catheterization and magnetic resonance imaging. In accordance with echocardiogram, magnetic resonance imaging showed global thickening of the free and septal wall in the first case and apical thickening in the second case. The alteration of the tissue component described by magnetic resonance imaging is in agreement with the histologic description of endomyocardial biopsy. Magnetic resonance imaging is a useful method for the diagnosis of cardiomyopathy.