Efficiency of some drugs in the treatment of periodontitis in combination with corrective treatment of thyroid function was evaluated in 70 patients with hypo- and hyperthyrosis with different initial level of nonspecific resistance. The therapeutic complex including drugs commonly used in the treatment of periodontitis and irrigation of the periodontium with lithium chloride and chlorohexidine solutions was highly effective in patients with thyroid dysfunction and relatively favorable status of nonspecific resistance of the organism. In patients with hypo- and hyperthyrosis with poor nonspecific resistance the best effect in the treatment of periodontitis was attained with potassium orotate as an immunomodulator and lithium chloride.