The authors investigated 998 organ-donors for Human cytomegalovirus seroprevalence. The donors were divided into three age-groups. In organ-donors the seroprevalence was found to be 84%. A study was also conducted on a fourth group consisting of 200 residents from an old-age home. The youngest donor was 2 years of age, the eldest old-age home resident was of 92 years. The examined persons represent the hungarian population. It was found that as the result of the investigation of all 1198 subjects, the Human cytomegalovirus overall seroprevalence in Hungary is 86%. The age specific prevalence increases starting from 73% in the first group (2 to 20 years old) to 99% in the fourth group (71 to 92 years old). This has indicated that most of the population acquired the primary infection in the childhood or during early adulthood. According to these results the authors resumed that in Hungary the Human cytomegalovirus seroprevalence is high. This would cause problems when a seronegative organ-recipient needs an organ transplantation. Between males and females a significant difference of Human cytomegalovirus seroprevalence was found: 89% of females were seropositive in contrast to 81% of males (p < 0.05). The organ-donors were also examined for the presence of HBsAg, anti-HCV and anti-HIV. 1.8% of donors were HbsAg positive, 0.9% were anti-HCV positive and 1 person was anti-HIV positive, but these results weren't verificated.