Purpose: The purpose of this study was to investigate differences of subjective, objective knowledge and educational need about contraceptives according to sex in college students. Methods: Data were collected by a self-administered questionnaire from 84 male and 111 female college students on May, 2008. PASW 18.0 program was used for data analysis. Results: There were significant differences in age, major, grade, place of residence, and experience of sexual intercourse between male and female college students. There was a significant difference in objective knowledge about contraceptives between the two groups, but no significant difference in subjective knowledge. The positive correlation was shown between subjective and objective knowledge about contraceptives. Even when demographic variables such as age, major, grade, place of residence, and experience of sexual intercourse were controlled, sex was a significant influencing factor on subjective and objective knowledge about contraceptives. Educational need about emergency contraceptive pills was significantly different and ranking of educational need about contraceptives was also different between the two groups. Conclusion: These results suggest that different education programs according to sex are needed to maximize the effect of contraceptive education and sexual characteristics are considered to give an education to college students.