The seasonal characteristic features of the efficacy of antioxidants in tetracycline affections of the liver were revealed in the experiments with 182 noninbred albino male rats. It was shown that sodium selenite had the most pronounced hepatoprotective effect in autumn and winter, while vitamin E was most effective in spring and summer. The combination of sodium selenite with vitamin E recovered impaired bile excretion in autumn, spring and summer. In winter, the recovery was less effective. It is concluded that the time factor plays a significant role in tetracycline hepatotoxicity and efficacy of antioxidants in tetracycline affections of the liver.