Cytomegalovirus infection is most common in infants under one year of age. The most common route of infection is through contact with blood and body fluids, and is classified as congenital or acquired depending on the timing of the infection. Congenital infections are those that occur in the fetus while the mother is still in the womb and can lead to stillbirths in early pregnancy and congenital birth defects in late pregnancy. Infection after birth can also lead to cholestatic hepatitis, hepatic impairment, or neurological impairment in children. The severity of cytomegalovirus infection is not proportional to the amount of virus, but depends on the duration of infection and the immune function of the child. Cytomegalovirus infections are often insidious and should usually be tested for cytomegalovirus antibodies and quantification of the virus in infancy. After diagnosis of cytomegalovirus infection, liver function, cranial CT or MRI, auditory brainstem response and fundus wide retinal examination should be performed and ganciclovir antiviral therapy should be administered as soon as possible if abnormalities are found.