This study identifies a theoretical mechanism through which communication with friends about sex influences sexual initiation in a sample of adolescents. The integrative model was used to assess the effect of attitudes, normative pressure, and self-efficacy on intentions to have sex in a sample of virgin adolescents. Results show that the constructs of the theory partially mediated the effect of communication with friends on subsequent sexual initiation. The effect of communication with friends on sexual initiation was not different for male and female adolescents. Overall, the results suggest how conversations with friends about sex influence adolescents' intentions to initiate sexual intercourse, which in turn influence subsequent sexual initiation. © The Author(s) 2010.