Employees of a children's hospital were studied to determine the prevalence of antibody to cytomegalovirus (CMV) and the incidence of CMV infection between 1984 and 1988 in relation to patient contact. At enrollment, 783 (63%) of 1250 employees had antibody to CMV. By logistic regression analysis, age greater than 30 years, black race, fewer than 16 years of education, employment for more than 1 year, female sex, and being married were each associated with seropositivity at enrollment. Three hundred workers who were seronegative initially were followed up; 13 seroconverted over a median follow-up interval of 1.96 years, 2.2% per year. Administrative, patient-care, laboratory, and support personnel were included among seroconverters. There were no statistically significant differences in the incidence of CMV infection when employees were grouped by job type, number of hours per week of patient contact, or nursing unit. The incidence of CMV among employees of a children's hospital was similar to the rate expected for the general population. Risk of CMV infection was not increased by patient contact in this setting.