This chapter traces theoretical and empirical progress in the study of human mating over the past few decades. Early pre-evolutionary formulations proposed that men and women were identical in their mating motivations. Most were simplistic, typically postulating a single motive for mating: the search for similarity, equity, or complementarity. Given the large sex differences in human reproductive biology, notably women bearing the burdens of internal fertilization and a greater obligatory parental investment, it would be extraordinarily unlikely that evolution by selection would fail to forge sex-differentiated mating strategies. Empirical research over the past 15 years has robustly confirmed evolutionary predictions in the domains of desire for sexual variety, the importance of fertility cues, and the importance of resource-provisioning. Recent work has revealed a hidden side of women's sexuality--a desire for extra-pair partners and the conditions under which this desire is expressed. We now have the theoretical and empirical outlines of an evolutionary formulation of human mating strategies.