This article provides a review of the past and current literature on the neurobiology of sexual function. The influence of endocrine, neurotransmitter, and central nervous system influences on male and female sexual function are discussed for sexual desire, arousal, and orgasm or ejaculation stages of sexual responding. Endocrine factors reviewed include the following: androgens, estrogens, progesterone, prolactin, oxytocin, cortisol, and pheromones. Neurotransmitters and neuropeptides discussed include nitric oxide, serotonin, dopamine, epinephrine, norepinephrine, opioids, acetylcholine, histamine, and γ-aminobutyric acid. Central nervous system influences on sexual function are discussed briefly with reference to brainstem regions, the hypothalamus, and the forebrain.