Neonatal pain is often undertreated. This is based on the assumption that because of the immature nervous system and the lack of the myelinisation preterm and newborn does not feel pain. It is confirmed by a number of articles that the fetus and neonate can experience and respond to painful events. This publication gives a brief overview of the ontogeny of the pain, short-and long-term postnatal consequences, as well as the perception of the possibility of a particularly frail child population: premature infants and neonates, based on animal and human studies.