Respiratory infections, especially pneumonia, are common in the first four weeks of life and are the cause of significant morbidity and mortality. Infants may be infected in utero, during labor and delivery, or postnatally. The etiology of neonatal respiratory infections varies widely and spans the spectrum from bacteria to protozoa. The exposure of the infant to maternal flora, the nursery environment, or household members plays an important role in determining the infecting pathogen. Diagnostic testing includes the chest film, CBC and routine bacterial cultures, but newer techniques such as latex agglutination tests for bacterial antigens or viral antigen detection or culture may be indicated in the appropriate clinical setting. This article reviews all of these aspects of respiratory infections and posits certain steps in their treatment.