The purpose of this study was to examine possible negative effects of fear-threat appeals encouraging AIDS prevention upon prejudice towards people with AIDS/HIV (PWA). Study 1 investigated the relationship between prejudice towards PWA and cognitive (perceived severity, probability of infection, efficacy of coping behavior etc.) and affective (fear of AIDS) factors as mediators of fear-threat appeals. 398 university students in Japan responded to the questionnaire concerning cognitive and affective factors on AIDS and prejudice towards PWA. A regression analysis revealed that perseived severity and fear of AIDS were both positively related to prejudice towards PWA, and that probability of HIV infection was negatively related to it. Study 2 examined the effect of fear-threat appeals on prejudice towards PWA. 472 university students in Japan participated to this experiment. Results agreed with those from Study 1 except for the fear of AIDS. The findings are interpreted as having possible implications for AIDS education.