While pheromones may act as social memory signals, oxytocin and vasopressin acting in the brain appear to be critical for the neural processing of olfactory signatures used for social discrimination. Evidence from a variety of laboratories using a range of animal models, as well as an array of molecular and pharmacological techniques, have helped to determine the neuroanatomical and functional roles oxytocin and vasopressin play in social cognition. In this review we discuss the considerable evidence for the roles of oxytocin and vasopressin in social recognition in rats and mice, as well as in offspring recognition in sheep and mate preference in monogamous voles.