Viral infection of the heart is relatively common, usually asymptomatic and has a spontaneous and complete resolution. It can, however, in rare cases, lead to substantial cardiac damage, development of viral cardiomyopathy and congestive heart failure. Viral cardiomyopathy is defined as viral persistence in a dilated heart. It may be accompanied by myocardial inflammation and then termed inflammatory viral cardiomyopathy (or viral myocarditis with cardiomegaly). If no inflammation is observed in the biopsy of a dilated heart (<14 lymphocytes and macrophages/mm ) the term viral cardiomyopathy or viral persistence in dilated cardiomyopathy should be applied. The diagnosis of myocarditis and viral cardiomyopathy can be made only by endomyocardial biopsy, implementing the WHO/WHF criteria, and PCR techniques for identification of viral genome. The most frequent cardiotropic viruses detected by endomyocardial biopsy are Parvo B19, enteroviruses, adenoviruses, cytomegalovirus, and less frequently Epstein-Barr virus, and influenza virus.