The smoking behavior of friends is a major risk factor for adolescent smoking uptake. To explore the social context of smoking experimentation and consolidation with a particular focus on friends, the authors interviewed both members of 14 young adult identical twin pairs who were discordant for smoking. The different smoking status of twins was connected to their different friendship groups and development of different identities. Smoking respondents gravitated to the behaviors and images of the peer group who smoked. Many nonsmokers felt strong pressure from their peers not to smoke and spoke about how the images conveyed by smoking were inconsistent with their peer group's image. Adolescents and young adults are aware of the messages that smoking can convey to others and exploit these images to construct a social identity.