Background. This article presents an analysis of prospective studies completed to date on the application of thermovisual imaging in the diagnosis and outcome monitoring of disorders of the knee joint. Material and methods. Three prospective studies were analyzed. Thermovisual exams were performed on the knees in a group of 170 patients with pain symptoms and 45 patients without knee pain. The intensity of the pain and joint dysfunction were evaluated on the basis of results from the Visual Analogue Scale (VAS), a specially developed patient chart, and the Knee-Leg Temperature Index (KLTI). Results. In the control group, the KLTI ranged from -1.5°C to -0.1°C. In the experimental group, the KLTI was between -1.8°C and +1.8°C before treatment, as compared to a range from -1.6°C to +1°C after treatment. Statistical analysis showed that the level of perceived pain and degree of dysfunction correlated with changes in the KLTI.Conclusions. The application of thermovisual examination with calculation of the KLTI is a valuable supplement in the evaluation of outcome in knee disorders. The sensitivity and specificity of the KLTI is high in knee pain syndrome. The method used to analyze the thermovisual image should be modified when there are disease conditions that may alter the skin surface temperature distribution in the lower extremity.