Beauty is an abstract construct. We all have our own ideas about what is and is not beautiful--a particular song or painting, a man or woman. Accurately describing what exactly "it" is that makes the song, painting or person beautiful, however, is a daunting task. In this article, we attempt to make the case that beauty and physical attractiveness is a serious matter. We begin with a discussion of the role of beauty in evolutionary theory. Next, we turn to theories of the physiology of beauty, which focus on physical characteristics such as pathogen resistance, averageness, physical symmetry, body ratios, and youthfulness. We then describe changes in the societal standards of beauty through a discussion of the relatively recent history of mass media images of beauty. We then use the psychological construct of body image to begin to understand the nature of beauty on an individual level. The article concludes with a discussion of the things that we do to make ourselves more beautiful.