Thirty-four patients with congenital cytomegalovirus infection who were symptomatic as newborns were followed in a special clinic providing periodic medical and visual examinations as well as psychometric testing and audiometry. All patients had symptoms of congenital infection by 2 weeks of age, and 31 of 34 had virus isolated from urine within the first month of life. Age at latest follow-up varied from 9 months to 14 years with a mean of about 4 years. Ten patients died and 23 surviving patients had adequate follow-up examinations; all but two had evidence of central nervous system or auditory handicaps. Microcephaly was present in 16 (70%), mental retardation in 14 (61%), hearing loss in seven (30%), neuromuscular disorders in eight (35%), and chorioretinitis or optic atrophy in five (22%). Children with symptomatic congenital cytomegalovirus infection are at very high risk for handicaps that will significantly impair development.