It has been revealed that the hypothyreosis (subclinical as a rule) can be found after every method applied in treatment of the larynx cancer. Correlation of data obtained with the time function allowed to specify survival probability of patients in euthyreosis after therapy termination. Among the factors supposed to be involved in keeping patient's normal thyroid gland function the following have been taken into account: sex, age, stage of the neoclassic process, scope of the surgical intervention on the larynx and lymph nodes of the neck, thyroid gland surgery and dose of irradiation given in Gy/T at the time of radiotherapy. Substantial impact on hypothyreosis was attributed to: method of laryngeal cancer, treatment, the range of its structures removal and surgical intervention on thyroid gland (excision of the thyroid lobe or its translocation for larynx reconstruction). It was found that the probability of survival in euthyreosis in patients treated by surgery and by combined method was the least after laryngopharyngectomy. In 3 years follow up period after such a therapy it amounted to 75% for surgical method and 48% for combined one. It was evident that the dysfunction of the thyroid gland resulted mostly from combined method of laryngeal cancer therapy (even without surgical intervention on thyroid glad). The probability of survival in euthyreosis in those patients was the least of all and amounted to 78.7% after 1 year of therapy termination and 42.9% after 6. In patients treated with combined method and intervention on thyroid gland, the survival probability in euthyreosis was 25% after excision thyroid lobe and 20% after its translocation for larynx reconstruction. After exclusive surgical therapy the probability amounted to 96% and after radiotherapy 88.6%. Prolongation of the follow up after radiotherapy (over 1 year) didn't increase the number of patients with hypothyreosis. The necessity of the evaluation of the thyroid gland hormonal function in every one patient has been stressed. This should be done before treatment and 1, 6, and 12 months after the termination of the therapy, and then once a year.