The effects of thymogen, thymalin and vilosen in combination with antituberculous drugs (isoniazid, streptomycin, rifampicin) were studied on 240 CBA mice with experimental tuberculosis. Thymus preparations supplemented to the complex treatment of experimental tuberculosis significantly increased their lifespan, contributed to a decrease in the index of spleen weight lung density and significantly increased the count of T lymphocytes and their proliferative activity as compared to those on antituberculous drugs alone. Thymogen was found to be the most effective in the complex treatment of experimental tuberculosis, whereas vilosen was the least. Thymogen plus vilosen proved to be the most beneficial combination of drugs.