Using panel data from a junior high school system in an urban area of Florida, we examine whether adolescents' best same-sex and best opposite-sex friends' sexual intercourse behavior increases the likelihood that respondents who are virgins at round 1 will make the transition to intercourse between rounds of our study. We find no significant influence effects of friends of either sex for black males or females, or white males. In contrast, white females are influenced by the sexual behavior of both their best female friend and best male friend. A virgin white female whose best friends of both sexes were sexually experience at round 1 was almost certain to have sexual intercourse within the two years of our study.