In a group of endomyocardial biopsies (EMB), performed in 45 patients with the clinical diagnosis of suspect myocarditis or dilated cardiomyopathy, positive findings (including histologically suspect lesions) were made in 53.3% of first EMB. Myocarditis, particularly its focal or multifocal forms, is bound to pose a major challenge not only in clinical diagnosis but, often, also in histological diagnosis. Of paramount importance in this situation are 1) early specimen removal after the onset of clinical manifestations and before initiation of the appropriate therapy, 2) removal of a major number of specimens in a single EMB because of the potential of focal lesions.