In Neonatology, a subspeciality of paediatrics, medical care is given to newborn infants, especially the ill or premature newborn. It is a hospital-based speciality, and is usually practiced in neonatal intensive care units (NICUs).

The principal patients of neonatologists are newborn infants who are ill or require special medical care due to prematurity, low birth weight, intrauterine growth restriction, congenital malformations (birth defects), sepsis, pulmonary hypoplasia or birth asphyxia.