The role of cortisol in sexual behavior in the female musk shrew (Suncus murinus) was examined. High levels of cortisol were associated with sexual receptivity, as indicated by species-typical tail-wagging behavior, during brief(15-min) mating tests. When cortisol production was blocked by metyrapone, an 11-β-hydroxylase inhibitor, females exhibited reduced sexual behavior relative to controls, an effect that was reversed with acute cortisol replacement. These results indicate that cortisol facilitates, rather than inhibits, sexual behavior in this species and expands the comparative understanding of hypothalamic–pituitary–adrenal (HPA) effects on reproduction.