Cytomegalovirus (CMV) is the leading cause of congenital infection in developed countries, affecting 0.3 to 0.6% of all live births in Europe. Primary CMV infection occurs in 1 to 4% of seronegative women during pregnancy and may be transmitted to the fetus in 40% of cases. Up to 10% of intrauterine CMV infections result in symptomatic congenital disease at birth. Half of these children and 13% of those born with asymptomatic infection will develop long-term sequelae, especially neurosensory hearing loss and mental retardation. Accurate diagnosis of primary maternal and fetal infection is now possible using the avidity index of anti-CMV IgG and virological testing to detect the virus in amniotic fluid. Symptomatic congenital infection may be preventable using CMV hyperimmune globulin during pregnancy. The gold standard for diagnosis of congenital CMV infection is the detection of the virus in urine within the first 2 weeks of life by rapid cell culture techniques (shell vial) or nucleic acid amplification of viral DNA (PCR). Retrospective diagnosis can be achieved by detection of viral DNA by PCR in dried blood spots (Guthrie card) collected on filter paper in the first days of life. Currently available drugs for the treatment of congenital CMV include ganciclovir and its oral prodrug valganciclovir. Treatment with intravenous ganciclovir for six weeks may prevent hearing deterioration in children with symptomatic congenital CMV infection and central nervous system involvement. Valganciclovir may be an excellent alternative because of its good bio-availability, providing plasma concentrations similar to those achieved with intravenous ganciclovir.