Concentration of vitamin E (α-tocopherol) was studied in liver, kidney, heart, and skeletal muscle of 12 mammalian species, of which nine inhabited under natural conditions, while three were farm-bred. In the majority of the species the highest tocopherol content has been found as a rule in the animal liver and kidney. Essential differences have been revealed in distribution and level of α-tocopherol including those in taxonomically close species. These differences seem to be due to ecological peculiarities of the animals. The obtained results allow considering α-tocopherol as one of factors of maintenance of the natural antioxidant system at the steady level.