This paper reviews the common spectrum of medical diseases of the neonatal chest. Emphasis is on radiographic changes that have been produced by the introduction of new therapeutic maneuvers, particularly the use of artificial surfactant in treating hyaline membrane disease and the survival of profoundly premature newborns (less than 650 g). A discussion of meconium aspiration syndrome, neonatal pneumonia, transient tachypnea of the newborn, congenital lymphangiectasia, and congenital heart disease is also included. The effects on the neonatal chest radiograph of extracorporeal membrane oxygenation and high-frequency ventilation are also mentioned.