The relationship between participation in a sex education course in the public schools and premarital sexual behavior is studied using cross-sectional data from a national probability sample of 1177 male and female American college students interviewed in detail about their sexual behavior and sexual socialization experiences. There was no significant difference between the premarital heterosexual involvement of individuals who had attended a sex education course and those who had not. Furthermore, there were no differences between those who received information on birth control or coitus and those who did not. The implications of these findings for sex education programs are discussed and speculations about successful and unsuccessful programs are made.