Background: Youth risky sexual practices are associated with serious and long-term, and in somerncases, to life-threatening consequences. This is especially true when youth people engage in more thanrnone risky sexual Practices. Although several studies were conducted in different parts of the world tornunderstand the factors associated with risky sexual practices, little is known about the issue in Ethiopiarnin general and in Bishoftu town, in particular.rnObjectives: The objective of the present study was to assess the magnitude of risky sexual practices andrnassociated factors among high school students in Bishoftu town, Oromia regional state, Ethiopia fromrnDecember to February 2017rnMethods: A cross-sectional school based study was conducted using quantitative data collectionrnmethod. 461 people were included in the study. Data were collected using standard and structured selfrnadministered questionnaires. The collected data was entered into EPI info version 3.5 and analyzedrnusing SPSS Version 21. Binary logistic regression analysis was used to estimate odds ratio and assessrnthe association between the study variables. P-value less or equal to 0.05 was used as a cut off points forrnstatistical significance at 95% confidence level.rnResults:- A total of 455 students have participated in the study with the response rate of 98.7% Amongrnthe study participants 441 responded to for the specific question and 88 (19.3) were practiced sexualrnintercourse in their life time and out of these 44 (9.7% ) had experienced risky sexual practices. Thernminimum age at which the respondents started risky sexual practice was 12 years. Of the studyrnparticipants, 32 (7%) have never used any method of protective device. The significant number of studyrnparticipants 12 (2.6%) have multiple sexual partners. Alcohol consumption (AOR, 4.93; 95%CI: 1.93-rn12.62) and cigarette smoking (AOR, 4.04; 95%CI: 1.50-10.98) by the study participants are factorsrnsignificantly associated with youth risky sexual practices.rnConclusion and recommendation: About one in ten young people in the study schools have practicedrnrisky sexual behavior. A relatively higher proportion of sexually active participates reported usingrnprotective devices during sexual intercourse. Schools, community based programs, governmentrnauthorities and parents have to work through multi-sectoral approach in reducing substance use amongrnyouths and increasing their knowledge on risky sexual practice and its negative consequences.rnKey words: Risky sexual practice, young people, Bishoftu