NICU lighting is an important element of the environment in which preterm infants continue to develop. Although several researchers have conducted studies on the subject, the existing divergence among the findings and the recommendations of neonatal experts limit the generalization of the results of these studies to guide neonatal clinical practice. While nursing practices are based on evidence and recommendations, it is essential to provide a review of the elements in the literature related to the lighting of the neonatal intensive care units.