The main objective of this study was to investigate the prevalence and associated riskrnfactors of promiscuous sexual behavior among university students. To achieve this objective, arncross-sectional study was conducted among 374 students (220 males and 154 females) of AddisrnAbaba University and Kotebe University College using systematic sampling method. Thernrequired data were collected using a pilot tested questionnaire. Descriptive statistics, Pearsonrnproduct movement correlation (r), standard and stepwise multiple regression, independentrnsample t-test, and one-way analysis of variance (ANOVA) were used to analyze data with thernhelp of SPSS version 20. The results indicated that 46.4% (Male = 27.6%, Female = 18.8%) of thernparticipants were engaged in promiscuous sexual behavior. This sexual behavior wasrnsignificantly and positively associated with all the risk factors (positive attitude to the behavior,rnpeer pressure, freedom from parental control, financial problem, and the desire for materialrnpossession) included in the study. The results of standard multiple regression analysis revealedrnthat the combined contribution of these five risk factors that explains the variance inrnpromiscuous sexual behavior was significant (34.5%). The subsequent stepwise multiplernregression analysis identified only three factors (positive attitude, freedom from parentalrncontrol, and material possession) as significant predictors of the behavior that explain 33.8%.rnRegarding differences, the behavior was higher among males than females, third year studentsrnthan second and first years, and students from city administration/regional capital than rural. Inrnconclusion, nearly half of the students were engaged and apparently practiced promiscuousrnsexual behavior. The risk factors included in this study were significantly associated with thernbehavior and most of them significantly predicted it. In light of these findings, suggestions forrnintervention are noted.