Addressing stigma through social marketing campaigns has the potential to enhance currently low rates of treatment seeking and improve the well-being of individuals with the eating disorder bulimia nervosa. This study aimed to evaluate the persuasiveness of health messages designed to reduce stigma and improve mental health literacy about this disorder. A community sample of 1,936 adults (48.2% male, 51.8% female) from Victoria, Australia, provided (a) self-report information on knowledge and stigma about bulimia nervosa and (b) ratings of the persuasiveness of 9 brief health messages on dimensions of convincingness and likelihood of changing attitudes. Messages were rated moderately to very convincing and a little to moderately likely to change attitudes toward bulimia nervosa. The most persuasive messages were those that emphasized that bulimia nervosa is a serious mental illness and is not attributable to personal failings. Higher ratings of convincingness were associated with being female, with having more knowledge about bulimia nervosa, and with lower levels of stigma about bulimia nervosa. Higher ratings for likelihood of changing attitudes were associated with being female and with ratings of the convincingness of the corresponding message. This study provides direction for persuasive content to be included in social marketing campaigns to reduce stigma toward bulimia nervosa.