Abstract. Pneumonia is a form of acute respiratory infection that affects the lungs. The lungs are made up of small sacs called alveoli, which fill with air when a healthy person breathes. When an individual has pneumonia, the alveoli are filled with pus and fluid, which makes breathing painful and limits oxygen intake. Pneumonia is the most common serious bacterial infection in newborns after sepsis and is classified as • Early-onset pneumonia: Begins at or within hours of birth • Late-onset pneumonia: Begins after 7 days of age Late-onset pneumonia most commonly occurs in newborns in neonatal intensive care (NICUs) who need a breathing tube (endotracheal intubation) for lung problems. Having a breathing tube increases the risk of pneumonia. Various etiologic agents including bacteria, viruses and atypical organism are responsible for childhood pneumonia. Recent studies suggest that viruses are one of the major causes of childhood and newborn pneumonia. Among viruses, respiratory syncytial virus has got great attention and several recent studies are reporting it as an important organism for pneumonia. Lack of exclusive breast feeding during first six months, improper timing of start and content of complimentary feeding, anemia, undernutrition, indoor pollution due to tobacco smoking and use of coal and wood for cooking food and lack of vaccinations are important risk factors. Hypoxia is significantly associated with childhood pneumonia. Therefore, use of pulse oximetry should be encouraged for early detection and prompt treatment of hypoxia to prevent adverse outcomes. Among the available tools for risk of mortality assessment in children due to pneumonia, PREPARE score is the best but external validation will be needed. Children can be protected from pneumonia, it can be prevented with simple interventions, and it can be treated with low-cost, low-tech medication and care.