Methyl testosterone induces in patients a decrease in glucose tolerance. Rabbits, after prolonged treatment with methyl testosterone, showed a decreased sugar tolerance; no change followed a similar period of treatment with testosterone propionate. The liver glycogen of the methyl testosterone treated animals was markedly decreased, that of the testosterone propionate treated group slightly increased; but there was no change in muscle glycogen in either group. Thyroidectomized rabbits, receiving methyl testosterone failed to show a modified sugar tolerance. The liver glycogen of hypophysectomized rats receiving methyl testosterone was not significantly altered from that of untreated hypophysectomized controls. The modification in glucose tolerance and carbohydrate storage observed after prolonged adm. of methyl testosterone may thus be dependent upon the action of other endocrine glands.