Interest in sexuality and reproductive function does not cease when people begin to age. Instead, a new set of questions arises. Women want to know if it is safe to have babies in their late thirties and early forties. They want to know more about hot flashes and other symptoms of menopause-which ones are dangerous and which are merely uncomfortable. They are eager to learn about the relative risks and benefits of estrogen replacement therapy. Men, too, are concerned about age-related changes in their sexual function. Experts in reproductive physiology, gerontology, and genetics met at the National Institutes of Health in June of 1984 to discuss these and other concerns about aging and the reproductive system. The conference on Aging, Reproduc- tion, and the Climacteric was sponsored by the American Fertility Society, The National Institute on Aging, and the National Institute of Child Health and Human Development. This volume is based on the proceedings of that confer- ence.