University studentsare often viewed as being at higher risks to acquire STIs/HIV infection, and they are categorized under the ‘most at risk groups’. Hence, to tackle the problem of HIV/AIDS in university, designing HIV/AIDS prevention messages is mandatory. This study was made to assess Jimma’s University students HIV/AIDS prevention message framing preferences. To do that, out of total of 1290 third year students, 305 students were selected using Sloven’s sample size determination formula. Questionnaire and interview were used to get quantitative and qualitative data respectively. The results indicated that in terms of detection –related behaviors, both the survey and interview showed that students generally preferred loss-framed messages so that they would be influenced to get HIV testing. Similarly, regarding messages that have prevention-related themes, majorities of the students preferred negatively framed HIV/AIDS prevention messages. In conclusion, in relation to prevention behavior, the finding failed to meet what health message framing theory advocates i.e. prevention –related behaviors would be most effective when they are framed in gain-manner. On the other hand, in relation to detection behavior the finding conceded with the theory that advocates that detection related behaviors would be most effective when they are designed in loss frame. To recommend, other factors that influence students’ preferences of HIV/AIDS prevention message framing should be well studied.