The body mass index, and especially the lean/fat tissue ratio, are determinants of female fertility. In 1996, it was claimed that leptin might be the "missing link" between fat and reproduction. Leptin belongs to the adipokine family, which also contains adiponectin and resistin. Leptin and resistin impair insulin sensitivity, whereas adiponectin enhances it. Leptin is a potent stimulator of central GnRH and gonadotropin secretion, and, paradoxically, a potent inhibitor of ovarian steroidogenesis. The central roles of adiponectin and resistin are less clear In the ovary, adiponectin stimulates steroidogenesis by granulosa cells. Recent data point to the existence of a distinct lipid metabolism in the ovary. Its role in female reproduction will provide an exciting field of research in coming years.