Near-infrared spectroscopy (NIRS) is a noninvasive technique that monitors regional tissue oxygenation reflecting perfusion status. Near-infrared spectroscopy has the ability to continuously and simultaneously monitor tissue perfusion in different organ systems at the bedside without interrupting routine care. Research has demonstrated its benefit in monitoring cerebral, intestinal, and renal perfusion to detect potential ischemic episodes. Near-infrared spectroscopy can augment current physiologic monitoring to increase awareness of abnormal perfusion status in the preterm population and potentially reduce risks associated with many diseases that may lead to ischemic injury. This article provides an overview describing NIRS technology and function, its current use in neonatology, and pertinent research findings illustrating its benefit in the neonatal population. Near-infrared spectroscopy may evolve into an important diagnostic and prognostic tool for neonatal treatment and outcome.