Evolutionary psychology provides a powerful theoretical perspective with which to understand the psychology of romantic attraction and relationship initiation. In seeking and initiating sexual and romantic relationships, people face substantial challenges, such as finding suitable partners, navigating conflicts of interest with those partners, competing with potential same-sex rivals, and warding off potential infidelity. People possess a variety of adaptive psychological and physiological mechanisms designed to help them deal with these challenges. This chapter describes several of the mechanisms that help people solve challenges associated with romantic attraction, intrasexual competition, and conflict between the sexes. After discussing many of the classic investigations in this area, the chapter highlights several recent lines of investigation, including research on lower-order perceptual processes and research on psychological and behavioral changes across the menstrual cycle. The chapter also outlines emerging trends in contemporary research, including (1) integrating theories of evolution, learning, and culture; (2) placing a stronger emphasis on the situational triggers of evolved mating mechanisms; and (3) developing a greater orientation toward applied research.