The authors analysed the data obtained in examination of 106 patients with carcinoma of the thyroid gland residing in the Mountaineous-Altai region endemic by goiter. A conclusion was drawn that in the great majority of the aforesaid patients an important etiological factor in the development of malignant tumour was nodular and diffuse-nodular goiter. In patients with carcinoma of the thyroid gland residing the mentioned region the blood iodine, cobalt, and copper content was much greater than in healthy persons. Iodine concentration in the tumour tissue of the thyroid gland was diminished, and of copper and cobalt--increased in comparison with such in healthy tissue. Blood iodine content in patients with carcinoma, and iodine in the tumour tissue of the thyroid gland was much less, and of copper and cobalt--increased in comparison with such in patients with endemic goiter. Deficiency of trace elements (iodine, copper, cobalt) in the surrounding environment of the endemic regions of the Mountaneous-Altai and the change of their content in the organism of patients with carcinoma of the thyroid gland permitted to refer this disease to geographical pathology.