Folliculogenesis in the adult ovary proceeds from quiescent primordial follicles through several developmental stages that culminate in the release of oocytes for fertilization and terminal differentiation of follicles into corpora lutea. Multiple developmental pathways control growth of oocytes and differentiation of somatic cells of the follicle. Growth factors of the transforming growth factor beta family play prominent roles during follicle development. Recent studies have begun to examine the role of additional developmentally important growth factor families, such as the Hedgehog, Wnt, and Notch families. This review summarizes recent developments on these signaling pathways in the adult mammalian ovary.