Forty experimental AIDS posters were prepared using 10 different pictures and 4 different printed messages relating to disease severity, personal vulnerability (PV), and response efficacy (RE). Subject characteristics examined include gender, age, ethnicity, and group membership (GM) with particular focus on effectiveness of elements of visual content. Using the Thurstone method of equal-appearing intervals subjects sorted the posters into five categories according to judged effectiveness in promoting condom use to prevent AIDS, and, in interviews, gave reasons for their particular responses. Results from this study reveal high severity/fear posters are significantly more effective than the low-severity/fear posters, but RE and PV are significant only in interactions with other variables. Although age, gender, ethnicity, and GM did not overall influence effectiveness, GM and age significantly affected severity/fear level, and RE, respectively. The findings suggest that this fear appeal approach can be an effective method in AIDS education programs. 31 references, 21 tables, and 1 figure (Author abstract modified)