The case histories of 414 patients who were operated on for mild diseases of the thyroid gland (DTH) were retrospectively studied. The study is aimed at studying the cytological material in the preoperative period and the comparative assessment of the postoperative histological material of patients operated on for the thyroid gland. As a result of the study, it was found that the share of nodular goiter with euthyroid function (UEZ) and multinodular euthyroid goiter (MUEZ) accounts for 269 patients, which is 65%. In 87 patients (21%), diffuse-toxic goiter (DTG) and nodular toxic goiter with the formation of functional autonomy (FA) were revealed; autoimmune thyroiditis (AIT) in 58 cases (14%). All 414 patients with tonic aspiration biopsy of the thyroid gland showed good changes in the cytological material. After the diagnosis, preoperative preparation, 294 patients (71%) out of 414 underwent thyroidectmia with DTZ, FA, with MUEZ and a significant increase in thyroid gland volume. Hemityroidectomy was performed in 178 patients (29%) with one-sided nodular lesion of the thyroid gland with preserved normal hormonal background. In 94% of cases, there is a coincidence of cytological and histological studies, a benign result of a biopsy material was confirmed in 389 patients. In 6% of cases (25 patients), there is a discrepancy between cytological and histological studies.