The presence of antibodies against cytomegalovirus (CMV)-induced immediate-early antigens (IEA), early antigens (EA) and late antigens (LA) was sought in 500 healthy blood donors. Antibodies to late antigens were detected in 76% and antibodies to immediate-early and early antigens were detected in 9.6% and 10.2%, respectively. The incidence of antibodies to CMV-induced immediate-early and early antigens increased with age, was higher in females than in males and was related to high values for antibodies against CMV late antigens. Since antibodies to CMV immediate-early and early antigens are significantly associated with active CMV infection, criteria for choosing blood samples unlikely to transmit infective CMV are evaluated.