Estrogens and androgens, the female and male sex hormones responsible for gender dimorphism and reproduction, play also a very important role in tissues and organs that are not directly involved in procreation. In fact, withdrawal of the effects of estrogens at menopause from nonreproductive tissues like the skeleton, the cardiovascular system, and the brain, is a major risk factor for the development of osteoporosis, coronary artery disease, stroke, and perhaps neurodegenerative diseases like Alzheimers. On the other hand, continuous exposure of reproductive tissues to estrogen during the postreproductive part of life, is a risk factor for the development of breast, ovarian, and uterine cancer. During the last decade, there have been significant advances in our understanding of the mechanism of action of sex steroids on the skeleton, the cardiovascular system, and the central nervous system. The purpose of this perspective is to provide a brief outline of these advances with an emphasis on the emergence of several thematic similarities in the action of sex steroids on nonreproductive tissues. For more thorough discussion of this topic, the reader is referred to recent review articles (1–5).