Between 1987 and 1994, the prevalence of antibodies to Cytomegalovirus (CMV) was determined by ELISA in 19,043 subjects in the population of Parma (Northern Italy). The overall prevalence was 71.8%. The age specific prevalence increases starting from 28% in two year-olds to 95.7% in 45-54 year-old subjects. Profiles of antibody production during primary and recurrent infection were analyzed and correlated with virus presence in clinical samples showing correspondence between virus excretion and increasing IgG levels. A longitudinal study of CMV infection was undertaken in 1045 pregnant women and their babies. Rate of infection during pregnancy was 2.34% and rate of congenital infection was 0.57%. Results also indicate that mothers are the major source of perinatal infection (contaminated genital secretions and milk) and confirm the usefulness of monitoring antibody status and virus excretion of mother and neonate at birth.