Relatively little is known about the extent to which health campaigns can play a constructive role in reducing HIV/AIDS-related stigma. The Malawi Radio Diaries is a program in which HIV-positive men and women openly discuss day-to-day events in their lives with the goal of reducing stigma in the population. Adopting a social marketing perspective, we analyze the various components of the Radio Diaries program in terms of three of the "Four P's": product (stigma reduction), place (radio), and promotion (the program itself). We first investigated the important dimensions of stigma and then developed a model to test the demographic and psychosocial correlates of these dimensions. A midterm household survey was then used to determine the relationship between exposure to the Radio Diaries program and stigma. In multivariate analyses, lower education and knowledge were associated with stronger beliefs that persons living with HIV should be isolated from others. Exposure to the Radio Diaries program did not have a main-effect on stigma, but there was a significant interaction between exposure and efficacy to reduce number of partners such that there was little difference in stigma by exposure level for those with low efficacy, but a significant difference by exposure level for those with high efficacy. Findings are discussed in terms of social marketing principles.