We investigated the possibility that norepinephrine from the human ovary is released after nerve stimulation and that this neurotransmitter is coupled to a steroidogenic response. Biologically significant levels of both norepinephrine and dopamine were found in human ovarian biopsies. [³H]norepinephrine incorporated in vitro was readily released by electrical stimulation in a Ca²⁺-dependent process. Ovarian membrane preparations exhibited specific binding sites for the β-adrenergic antagonist [³H]dihydroalprenolol. displacement of [³H]dihydroalprenolol with zinterol (a specific β₂-agonist, indicated that 72% of these sites were type β₂-receptors. β-receptors were also present on granulosa cells. Stimulation of granulosa cells with luteinizing hormone or the β-agonist isoproterenol increased the release of progesterone after 4 d in culture. These results suggest that the sympathetic nerves present in human ovary are coupled to β-adrenergic receptors present in endocrine cells and, as in nonprimate mammals, appear to participate in the regulation of ovarian function.