An online survey of a nationally representative sample of U.S. men aged 18–40 assessed trait predictors of social networking site use as well as two forms of visual self-presentation: editing one’s image in photographs posted on social networking sites (SNSs) and posting “selfies,” or pictures users take of themselves. We examined the Dark Triad (i.e., narcissism, Machiavellianism, and psychopathy) and trait self-objectification as predictors. Self-objectification and narcissism predicted time spent on SNSs. Narcissism and psychopathy predicted the number of selfies posted, whereas narcissism and self-objectification predicted editing photographs of oneself posted on SNSs. We discuss selective self-presentation processes on social media and how these traits may influence interpersonal relationship development in computer-mediated communication.