Objectives: Previous studies have reported mixed results in reducing the prevalence of tobacco use among young people. The present study investigates the influence of a combined emotions (fear and anger) approach to strengthen the persuasive impact of anti-smoking messages aimed at young smokers. Study design: The study adopts a between-subject design experiment. Methods: Participants were exposed to either a fear appeal or a fear and anger appeal message, after which they answered questions about their emotions, perceived message effectiveness, and intention to reduce cigarette consumption and to quit smoking. An original measure of the co-occurrence of emotions felt by the participants (minimum [MIN] score) was used and mediation analyses were conducted to test the relationship between the emotional content of the message and behavioral intentions through the co-occurrence of fear and anger and perceived message effectiveness. Results: The findings show that the co-occurrence of fear and anger felt by individuals and perceived message effectiveness serially mediate the positive influence of a fear and anger appeal message compared to a fear alone appeal on changes in intention behavior (intention to reduce cigarette consumption, indirect effect = 0.152, 95% confidence interval (CI) [0.014, 0.340], and intention to quit smoking, indirect effect = 0.236, 95% CI [0.096, 0.413]). Conclusions: The study shows the interest of combining negative emotions in prevention messages and offers guidance for government agencies responsible for tobacco control policies to help them improve the effectiveness of anti-smoking messages. © 2022 The Royal Society for Public Health