The microcirculation is a key compartment of cardiovascular system responsible for delivering oxygen to the tissue cells. Its function can be compromised by a wide range of conditions, such as infection, trauma and extensive surgery. Microcirculatory dysfunction can lead to loss of hemodynamic coherence, so macrocirculatory monitoring is not sufficient for evaluation of tissue perfusion. Microcirculatory function can be monitored indirectly by evaluating tissue oxygenation (pulse oximetry, NIRS, central and mixed venous oxygen saturation), or by measuring tissue concentrations of metabolic end-products, most important being lactate. Other methods allow direct visualization of the erythrocytes inside the capillaries (OPS, SDF, Cytocam-IDF) and enable flow velocity measurement (LDF). Brain tissue is most susceptible to hypoxic injury and cerebral perfusion may be disrupted by large number of local and systemic conditions. Therefore, it is necessary to monitor brain oxygenation and perfusion, for which there are several methods (TCD, TDP, SjvO2, PbtO2, cerebral microdialysis) available. Microcirculation and oxygenation monitoring is of outmost importance, not only to be able to diagnose microcirculatory disorders, but also to evaluate the response to therapeutic procedures. The main goal of treatment is establishment of adequate tissue oxygenation, microcirculation, and hemodynamic coherence. Non-invasive methods that allow continuous monitoring are prefered when monitoring these variables.