This case report describes congenital nephrotic syndrome in a 2-month-old girl associated with cytomegalovirus infection. Histological examination on renal biopsy showed diffuse mesangial sclerosis and cytomegalic inclusion bodies in the tubular cells and in some glomeruli. Cytomegalovirus (CMV) polymerase chain reaction (PCR) titer in serum was high. Remission of pulmonary and renal symptoms was achieved with ganciclovir in 3 weeks. No recurrence of proteinuria was observed during the follow-up period of 14 months. These finding suggested a causal relationship between congenital nephrotic syndrome and cytomegalovirus infection.