The effect of a long-term peroral introduction of oxymethylfurfurol on the organism of albino rats was studied. The compound was administered to rats via a tube 6 days in a week for 11 months in doses of 40, 80 and 160 mg/kg with controls receiving water in place of the oxymethylfurfurol. The rats receiving 160 mg of oxymethylfurfurol per kg of body weight demonstrated a temporary rise in the level of gamma-globulin in the blood serum, an increase in the relative weight of the spleen, a tendency towards a greater activity of tributyrinase in the hepatic tissue. Dases of 40 and 80 mg/kg did not affect the protein and lipids metabolism characteristics under study, the suprarenal content of ascorbic acid, the activity of the liver succinate-dehydrogenase, the morphological structure of the internal organs, nor the general condition and dynamic changes in the weight of the animals. From the results obtained it follows that the possibility of any toxic action of oxymethylfurfurol on the albino rats with its peroral administration in a dose of 80 mg/kg and below is ruled out. By adopting a 40-fold safety margin the acceptable daily intake (ADI) of oxymethylfurfurol with food of man is estimated at up to 2 mg/kg of body weight.