Purpose: to study features of a functional condition of thyroid gland in the perimenopausal period at the women in iodine deficient region. Material and methods. Population study of 512 women in the age of 45—55 years chosen by a casual way on a database of obligatory medical insurance of Ekaterinburg. The inspection included definition thyroid stimulating hormone, autoantibodies to thyroperoxidase, ultrasonic research of thyroid gland. Three groups are allocated: premenopause (n = 282); natural menopause till 2 years (n = 94); natural menopause more than 2 years (n = 90). Results. The disfunction of thyroid gland revealed at 19.5% (100/512) perimenopausal women. The most often infringement was hypothyroidism — 16.7% (86/512). Its reasons were autoimmune thyroiditis — 86.0% (74/86) and surgical intervention on thyroid gland — 14.0% (12/86). The frequency of hypothyroidism was higher in 1,9 times (р = 0.03) per first two years of menopause, and was higher in 1,6 times (р > 0.05) the next years, than in premenopause. Hyperthyroidism met more often per first two years of menopause (р > 0.05). Autoimmune thyroid pathology per first two years was at 25.5% (24/94) women, that in 1,9 times is more often (р = 0.03), than in premenopause — 13.5% (38/282), and in 1.6 times are more often (Р > 0.05), than in menopause more than 2 years — 15.6% (14/90). Conclusions. During perimenopause most of all functional thyroid disorders revealed per the first two years of menopause. These infringements frequently have autoimmune nature. These changes can be temporary and require the observation in dynamics. Key words: thyroid gland, hypothyroidism, menopause.