Inflammatory heart disease is causally linked with progressive left ventricular dysfunction and congestive heart failure. In childhood, infection with parvovirus B19 (PVB19) is usually benign, causing erythema infectiosum. However, severe fetal PVB19 infection may be associated with hydrops fetalis and fetal death caused by myocarditis. Here we report a PVB19-induced myocarditis in a previously healthy 37-year-old patient admitted to the hospital because of chest pain and dyspnea due to left ventricular dysfunction. Four weeks after the onset of symptoms, we found lymphocytic infiltrates and PVB19 genome in left ventricular endomyocardial biopsy specimens. Consistently, acute PVB19 infection was indicated serologically by elevated IgM titers and the presence of PVB19 genome in peripheral blood lymphocytes. In conclusion, PVB19 infection may be complicated by acute myocarditis in immunocompetent adults. Because PVB19 myocarditis may progress to chronic dilated cardiomyopathy, early diagnosis by endomyocardial biopsy is important to initiate anti-inflammatory treatment.