SUMMARYAdenosine triphosphate (ATP) is released from the cell by multiple mechanisms. The extracellular form of this purine is processed by ectonucleotidases, resulting in a variety of dephosphorylated metabolites that can bind to specific receptors found in the membrane of target cells; such purinergic signaling is important as an autocrine‐paracrine intercellular communication system that influences tissue physiology. In this review, we summarize the studies analyzing purinergic activity in the ovary, which can modulate cellular physiology—including sensitivity to gonadotropins—in several ovarian cell types, including the cumulus‐cell complex, granulosa cells, theca cells, and the ovarian surface epithelium. These functions support a role for ATP as an important intra‐ovarian messenger, and open new lines of research that can improve our understanding of mechanisms regulating ovarian function and the fine‐tuning of folliculogenesis.Mol. Reprod. Dev. 82: 839–848, 2015. © 2015 Wiley Periodicals, Inc.