A 6-week-old immunocompetent girl developed protein-losing gastroenteropathy (PLGE) and retinitis associated with cytomegalovirus (CMV) infection. At presentation, CMV antigenaemia (6 cells/46,000 white blood cells) and its DNA were detected in the patients blood and in the mothers milk. Intravenous ganciclovir and -globulin rapidly ameliorated all symptoms and CMV antigenaemia disappeared. No immunological defects were identified in this patient. To the best of our knowledge, this case involves the youngest known immunocompetent patient demonstrating CMV-induced PLGE and retinitis. Conclusion:breast-feeding by a cytomegalovirus-positive mother can be a primary cause of early onset cytomegalovirus infection in infants.