Congenital cytomegalovirus (CMV) infection is an important cause of hearing impairment, mental retardation, and cerebral palsy. Principal sources of infection during pregnancy are young children and intimate contacts. Prevention of maternal and congenital CMV infection depends on counseling women regarding the sources of infection and hygienic measures that might prevent infection. There is currently insufficient evidence to support use of antiviral treatment or passive immunization for postexposure prophylaxis of pregnant women or as a maternal treatment aimed at preventing fetal infection. Vaccines for CMV are under development but it will be a number of years before one is licensed.