An epidemiological study for detection of IgG and IgM antibodies against cytomegalovirus, Epstein-Barr virus and Herpes simplex virus was evaluated in a random population of apparently healthy Greek blood donors from which only HIV and HBV carriers were excluded. The prevalence of IgM antibodies was found to be relatively low at 4.4%, 6.1% and 7.7% respectively. The presence of these antibodies plays an important role when transfusing immunocompromised and transplanted subjects.