The influence of norethynodrel (the major component of the oral contraceptive Enovid) on the sialic acid content of the rat submandibular gland was studied. Sialic acid content was greatly reduced 70 days after ovariectomy. Tabulated results show that norethynodrel injected subcutaneously in daily doses of .075 and 3 mg for 10 days increased the concentration of glandular sialic acid in both intact and ovariectomized rats with a greater response at 3-mg doses. Total sialic acid content increased despite a decrease in the absolute weight of the submandibular gland in intact and ovariectomized rats receiving 3-mg doses. Evidence indicates that sialic acid content of the submandibular glands is dependent on ovarian secretions and that responses to norethynodrel are due to its estrogenic properties as revealed in its capacity to increase uterine weight in ovariectomized rats (from 75 mg for control rats to 237 mg at the 3-mg dosage).