The prevalence of serum antibodies to cytomegalovirus among nursing personnel was studied with regard to the risk of infection among female nurses of childbearing age. Nursing staff considered at risk were studied in the hospital areas of hematology and oncology, the nursery, the burn unit, renal transplant and dialysis units, and intensive care units. The nursing staff of the psychiatric units and nonpediatric outpatient units were included as the low risk population. A total of 374 nurses participated in the investigation. All participants completed a personal history survey and gave blood samples for determination of cytomegalovirus antibodies. Antibodies were assayed by an indirect immunofluorescent technique and by enzyme immunoassay using a solid phase microplate method. A total of 56 percent of the total nursing population surveyed had antibodies to cytomegalovirus. The mean age of the individuals with positive antibody responses was 34 years. The mean age of the individuals with negative antibody responses was 29 years. A total of 87 percent of the black nurses were seropositive relative to a total of 48 percent of the white nurses. Significant positive correlations between age, race, and seropositivity were established. No significant differences for seropositivity were determined among hospital areas or between nursing staff and clerical staff. The authors conclude that nursing is not a major risk factor for the acquisition of cytomegalovirus infection.