The aim of the study was to assess the effectiveness of cytoflavin inclusion in complex treatment of patients with hypoparathyroidism occurring after thyroid surgery. To do this, an analysis of treatment of 54 patients who received surgical treatment for thyroid diseases of various etiologies. Depending on the scheme of post-operative medical therapy, the patients were divided into 2 groups: group I patients (27 persons) received basic therapy according to regulatory documents, II of the group (27 patients) in addition cytoflavin intravenous drip of 10 ml to 200 ml 0.9% NaCl for 7 days. In addition to standard clinical and laboratory examination, all patients were studied and the level of active ionized Ca2+ and PTH, oxidation products of the modified protein, lipid peroxidation and antioksidazation system dynamics — 1, 3 and 7 days after surgery. It was revealed that in the first days after the surgical treatment of patients significantly reduced the levels of ionized Ca2+ and PTH that may be regarded as signs of postoperative hypoparathyroidism, as well as the activation of the system of lipid peroxidation and antioxidant system depression. Turning cytoflavin in drug regimens improved the efficiency of the treatment, which was manifested in arresting to 7 days of monitoring signs of hypoparathyroidism, improve tissue oxygenation and restoring the balance by reducing the activity of the system of lipid peroxidation and antioxidant system strengthening.