The brain is an organ highly sensitive to ischemia due to its high metabolic rate and the fact that, for normal functioning, a continuous and strictly regulated cerebral blood flow (CBF) and adequate tissue supply with oxygen are necessary. Ensuring a proper balance between cerebral oxygenation and metabolic demands is especially important in patients with acute brain injuries, as these patients are at high risk of secondary brain injuries, the prevention of which is the main goal of brain oxygenation monitoring. Although neuroimaging techniques such as PET, CT, and MRI are commonly used in clinical practice to measure blood flow, there is a need for their supplementation with continuous methods of CBF monitoring at the patient's bedside, for which two methods are available: transcranial Doppler ultrasound (TCD) and thermal diffusion flowmetry (TDF). Brain oxygenation monitoring enables rapid identification of potential problems with oxygen supply and early intervention in order to prevent further tissue damage and neurological function impairment. Available monitoring methods can be divided into invasive, such as jugular venous oxygen saturation (SjvO2) and monitoring of the partial pressure of oxygen in brain tissue (PbtO2), and non-invasive methods, currently including near-infrared spectroscopy (NIRS). Although each of these methods has its advantages and disadvantages, as well as specific clinical applications, there is a greater focus on non-invasive methods because they are quick, allow continuous monitoring of changes in real time and, despite being somewhat less precise, cause fewer complications compared to invasive monitoring. Despite their predominantly experimental use at present, through further research into their effectiveness, described brain oxygenation monitoring methods have great potential to become an essential part of standard neuromonitoring and patient care in anesthesiology.