Background: Neglecting the sexual and reproductive health of the youth may potentially lead to high social and economic costs, both at present and in the future. The aim of this study was to assess the risk of sexual behavior and practice of Public college students in Harar, Ethiopia. Methods: A cross-sectional study was conducted across two public colleges in Harar, Ethiopia in 2019. 385 participants provided information on their socio-demographic characteristics, sexual behavior and practice, their risk perception towards HIV/AIDS, and STIs through a self-administered questionnaire. SPSS version 20 was used for data analysis. Results: The age range of the respondents was between 17 and 31. 207 out of 385 subjects were female. Around half 167 (43.4%) of the respondents were sexually active. About 33.5% of the respondents had experienced premarital sex before the age of 18. 52.2% of the participants had sexual activity with multiple partners. Among 31 (8.1%) of them developed a pregnancy; all pregnancies were unplanned and ended up with abortion, however. Conclusion: Significant numbers of students are assumed to have risky sexual behavior, which may increase an individualchr('39')s risk of acquiring HIV/ AIDS. Accordingly, it is imperative that college students practice healthy behavioral modification through the use of such available services as condoms and contraceptives.