We performed a 5-year review of 40 patients less than or equal to 30 days of age with viral pneumonia. Isolates included respiratory syncytial virus (55%), enteroviruses (15%), rhinoviruses (15%), adenoviruses (10%), parainfluenza virus (7.5%) and herpes simplex virus (5%). Most infants were previously healthy but had ill family members. Nine were born at less than 37 weeks of gestation. Symptoms and signs included tachypnea, decreased feeding, cough, cyanosis, lethargy, retractions, apnea, bradycardia, seizures and depressed consciousness. Seasonality and clinical features, but not radiographic patterns, suggested specific pathogens. Patients were moderately to severely ill. The median duration of hospitalization was 7 days; therapies administered included oxygen (90%), mechanical ventilation (45%), blood transfusions (25%) and supplemental oxygen after discharge (27%). The case fatality rate was 7.5%. Prematurity, ill appearance at presentation, lobar consolidation and adenovirus infection were risk factors for severe disease.