The authors present the results of a thermographic study of the thyroid in patients with diffuse and nodular forms of the goiter. The thermograms and the thermometry data were analysed in 47 patients with diffuse forms of the goiter and in 105 patients with single "cold" and "hot" nodes in the thyroid. Thermography was shown to be a simple harmless method that makes it possible to study the heat production of the thyroid in different pathological processes, e.g. in "cold" nodes delta t over the node was on an average higher by 1 degree C as compared to the symmetrical zone, in "hot" nodes this difference was insignificant, and in diffuse forms of the goiter an isothermal picture was observed. The authors are of opinion that in diffuse forms of the goiter thermography should be considered appropriate as a test for dynamic observation in the process of drug therapy. In "cold" nodes, thermography may serve as a rough test for the choice of patients with suspected thyroid tumors. In "hot" nodes, thermography, according to the authors, is though irrelevant.