Researchers have spent decades investigating factors in attraction; biological variables, cultural norms, and social pressures have all had their time in the spotlight. Humans are complicated animals and each of these realms have shown measurable effects. However, evolutionary approaches provide a unifying theory that subsumes and explains each of these factors and how they interact to create intricate yet predictable patterns in human mating behavior. In this chapter, we give a brief summary of major factors influencing attractiveness as perceived by men, including biological factors such as age and ovulatory status but also social factors such as exposure to highly attractive, or simply novel, women. Understanding how attractiveness can vary over time and within relationships can be useful, not only to research but also in applied clinical fields such as couples’ and marital therapy.