Near infrared spectroscopy systems are relied on today as adjuncts to aid intensive care and guide intraoperative and anaesthetic management. Ongoing evolution has given these technologies increasing clinical relevance. The original pioneering work in newborn infants established a role for NIRS as a means of monitoring changes in brain blood volume and oxygenation relevant to their care. Studies in animal models established that the onset of spinal cord ischemia could be detected in real time; these led to the technology being applied as an adjunct to prevent spinal cord damage during various surgical procedures where compromised spinal cord perfusion is a risk. Technical advances and innovation now make sensitive real-time hemodynamic and oxygenation monitoring of the spinal cord feasible using an invasive system; this has the potential to provide adjunctive care able to optimize perfusion and oxygen delivery at the site of injury following acute spinal trauma. In future, further miniaturization of brain and spinal cord systems, incorporation of multimodal sensors, advanced software and combination with parallel technologies will continue to expand the clinical role of NIRS as a means of enabling clinicians to optimize care of the brain and spinal cord.