BACKGROUND: Dieting prevention interventions have been relatively unsuccessful and may be more effective if they concentrate on messages known to be relatively high on persuasive properties. We aimed to identify anti-dieting messages rated most strongly on persuasive dimensions and participant characteristics that predicted message evaluations in adolescent girls. METHODS: Grade 7 and 8 girls completed questionnaires assessing risk factors for, and early symptoms of, eating disorders. Two weeks later, participants viewed on video seven messages (each 2-3 minutes long) frequently used to dissuade against dieting in prevention interventions and one control message. After viewing each message, participants rated it on a scale assessing the persuasive dimensions of Relevance, Believability, Emotional Response, and Intention to Diet. RESULTS AND CONCLUSIONS: A quarter to a third of participants felt less likely to go on a diet after viewing the messages. "Skipping meals makes you feel starved so you overeat and feel bad" and "Don't be fooled by the fad diets promoted in the media" were rated most strongly. Higher dieting, body dissatisfaction, and negative affect were generally associated with lower persuasive ratings, suggesting the importance of intervention prior to the establishment of dieting behaviors after which there is more message resistance. Age was also a predictor of Believability for some messages, supporting the importance of ensuring the age appropriateness of messages.