MUCH MORE is known about ovarian function in small mammals, especially laboratory rodents, than about the factors regulating cyclic ovarian function in primates. However, recent results, including our own, have enhanced the understanding of ovarian function in primates, bringing new and significant findings that now justify an assembly of knowledge on the regulation of the primate ovarian cycle. In this review, the major consideration is given to aspects of folliculogenesis in primate species. Where important similarities or differences in fundamental issues have been described in other mammals, limited discussion has been given to comparative aspects of follicular maturation. Consequently, we encourage readers of this subject to rely upon several scholarly reviews (1–7) that have recently developed comparative topics more fully than is either appropriate or intended here. Accordingly, we have restricted our attention to the dynamics of follicle growth during the primate ovarian cycle to focus on recent findings that have enhanced our understanding of the process of folliculogenesis in laboratory primates.