The content was studied of estriol, estradiol, progesterone, and testosterone in the blood of 30 women suffering from duodenal ulcer (DU). Of these, 15 female subjects were at reproductive age (with their menstrual function unimpaired), other 15 were in menopause. The results were compared with those obtained in essentially healthy women at similar ages. It is ascertained that in DU there take place changes in the ovarian hormonal function, that are especially pronounced in those female persons in the menopause (the progesterone level is decreased, that of testosterone strikingly increased). In women at reproductive age the relation of the revealed changes to DU is less convincing and is recordable in but a small proportion of the patients.