Health messages are designed to stimulate an active cognitive process in those audiences generally with little involvement. The Elaboration Likelihood Model by Petty and Cacioppo sustains that subjects with high involvement and those with low involvement react differently to the persuasive message to which they are exposed. One efficient way to capture the attention of the low involvement audiences is to insert the messages within an entertainment context. Our study attempted to analyze affective and cognitive processes to explain the impact of these new formats, fictional shorts for HIV/AIDS prevention. A 2 x 2 factorial design was used, with involvement in the AIDS issue (high/low) and the type of format (musical/dialogue) as independent variables. The finding showed the better the quality of the short (with dialogue style) the more negative affectivity was stimulated, also the more cognitive processing was induced, and a more favorable attitude towards preventive behavior was stimulated.