Immunohistochemical and molecular-pathological techniques have improved the diagnosis, but the incidence of virus-induced lethal myocarditis remains unclear. Therefore, it is of great interest to investigate postmortem myocardial samples in cases of sudden infant death syndrome (SIDS). Cytomegaloviruses are known as possible agents of myocarditis. Viral DNA was specifically isolated and amplified from formaldehyde-fixed material. At autopsy, myocardial samples were taken from 70 SIDS cases from different regions and investigated with PCR. Cytomegalovirus DNA was detected in 2 out of 70 cases. Our results emphasize the importance of modern molecular-pathological methods in cases of sudden unexpected death.