For 50 years 603 patients with the thyroid gland cancer were operated on, to whom 715 operative interventions were done. Before the Chernobyl disaster 395 patients were examined, after her--208. Differentiated forms of the thyroid gland cancer were diagnosed in 97.3% of patients, including papillary one--in 83.3%, follicular--in 14%. After the Chernobyl disaster the thyroid gland cancer diagnosis had improved significantly, it had become revealed on early stage. There were 5.6% patients with cancer operated for the thyroid gland diseases for 50 years (5%--before the disaster and 7.8%--after her). The clinical course of differentiated thyroid gland cancer permits to perform organpreserving operation no less than hemithyroidectomy in patients with T1-2N0M0 stage of the disease. The five-year survival index of patients with differentiated cancer had constituted 89%, the ten-year one--84%.