Urogenital problems in the elderly female population are experienced by one third of women from the age 50 years and onward. Symptoms from the lower urinary tract include incontinence, urethritis, and recurrent urinary tract infections. Atrophic changes within the bladder neck and urethra could be corrected by estrogen administration even at doses so low that endometrial proliferation is avoided. Hence such estrogens could be given without progestogen comedication. Control of micturition is a complex process of which estrogen deficiency is only one of several factors. The aging process with subsequent changes in membrane permeability, neuromuscular function, and collagen synthesis contributes to the local problems of control of micturition. In addition, the central control may also be affected by degenerative changes of the nervous system. Vaginal symptoms comprise dryness of vagina, dyspareunia, and recurrent vaginitis often followed by a fowl odor and discharge. The microflora with lactobacilli and low pH as seen in fertile women is gradually replaced by a mixed germ flora including several of the pathogenic organisms common in urinary tract infections. Vaginal pH increases from around 4 to between 6 and 7. It is a puzzling fact that the urogenital tissues seem to be more "sensitive" to estrogens than other tissues. Conformational changes of the estrogen receptor(s) brought about by the local cytokine milieu is one possibility to explain the situation. The systemic absorption of low-dose estrogen preparations is dependent on the status of the vaginal mucosa. Absorption is high when the vaginal mucosa is atrophic and gradually decreases (but not to zero) as the vaginal mucosa matures under estrogen influence. (Am J Obstet Gynecol 1998;178:S245-9.)