BACKGROUND Cytomegalovirus (CMV) pneumonitis may be severe, even lethal, following congenital infection or in premature infants with perinatal infection. OBJECTIVE To review the epidemiological, pathogenetic, clinical and therapeutic features of prenatal and perinatal CMV lung diseases. METHODS Evaluation of all published papers listed on PubMed describing CMV pneumonitis in infants. RESULTS CMV is frequent and severe in immunosuppressed infants but infrequent in full-term neonates and occurs more frequently after perinatal than after congenital infection, particularly in premature infants. In premature infants, CMV infection is often protracted and causes a diffuse interstitial pneumonitis leading to fibrosis and bronchopulmonary dysplasia (BPD). Congenital CMV infection should also be considered in newborns with severe acute respiratory distress syndrome and refractory respiratory failure with progression to early chronic lung disease. The association between breast milk-transmitted CMV and development of cystic lung disease and Wilson-Mikity syndrome has also been reported. Data on the efficacy of antiviral therapy for infants with respiratory CMV diseases are lacking and only anecdotal case reports are available. CONCLUSIONS Persistent CMV infection appears to cause a diffuse necrotizing pneumonitis with fibrosis leading to BPD, in both immunocompromised or preterm infants and, less frequently in immunocompetent infants. The role of antiviral therapy remains to be elucidated.