This study examined gender differences in college students' knowledge, attitudes, and sexual behaviors of 1,004 predominantly heterosexual students. Results indicated that students had limited knowledge about contraceptives and sexually transmitted infections (STIs). Females had a more positive view about contraceptives and males had more permissive attitudes about sex. Despite these differences, there was no difference in the age at which they became sexually active.The main differences between males' and females' behaviors related to their number of sexual partners and comfort communicating about sex. Our findings suggest a need to reevaluate how we educate youth about contraceptives and STIs. (Contains 1 table.)