BACKGROUND: The adolescent period is a time at which individuals explore and develop their sexuality, gender and sex role. These factors have a profound influence on a young person’s current and future health. It is believed that age at menarche is declining, and that premarital adolescent sexual activity is increasing. Clearly, if this change in behavior is not compensated by an increase in premarital use of contraception, it is expected that there will be an increase in the proportion of out-of-wedlock adolescent births, as well as an increase in the prevalence of induced abortion which ends in high proportion of maternal mortality rate. OBJECTIVE: The objective of this study is to assess pregnancy risk perception and contraceptive use among college student in Shashamane town. METHODS: A cross- sectional descriptive survey was carried out among college students in Shashamane Woreda, Western Arsi Zone, from February 15th to may 2011. A total of six hundred seventeen subjects were involved with response rate of 100%. To collect data, a pre- tested self administered questionnaire was used. RESULTS: Out of the total students 314(50.9%) were sexually active. The mean age for first sexual initiation was 17yrs with 1.4yrs of SD. The likelihood of becoming sexually active was lower among students from other Woreda than from Shashamane and two times higher among students who live with friends in rented house at significant level of association (AOR=0.5519;95%CI;0.3648,0.8349) and(AOR=2.44;95%CI;1.5581,3.8334) respectively. Out of the total respondent only 287(46.5%) knew the exact days of ovulation .Among the sexually active respondents, 164(52.2%) had ever used IX contraceptive . The odds of contraceptive use among students who have low perception about the weight of being pregnant is extremely low ( AOR=0.31;95%CI;0.19, 0.5) CONCLUSION: From this study, it was concluded that the age of the sexual debut among college youths were too early. Contraceptive utilization and self-risk perception toward unwanted pregnancy among youths were also very low. Youths also lack comprehensive knowledge about phase of ovulation. The likely hood of contraceptive use among students with low perception is low. RECOMMENDATION: IEC programs should be put on reproductive health in order to encourage the youths to delay sex and negotiate contraceptive use. Young people rely heavily up on interpersonal contacts for sexual information, peer based intervention should be implemented to ascertain that youths have access to accurate information.