The purpose of this study is to examine the effects and persuasive mechanisms of expository and narrative HPV vaccine messages targeted toward young men. The researcher used the Centers for Disease Control and Prevention’s HPV facts for men as a framework for the expository message condition. He also created two similar but distinct narratives that focused on HPV and men. The first narrative was informed by narrative persuasion studies in the social sciences and was labeled the academic narrative. The second narrative incorporated important elements of storytelling from literary theory and was labeled the classic narrative. A comparison condition, which presented a testimonial from a testicular cancer survivor, was also employed to compare against the effectiveness of the three experimental conditions. In the experiment, 258 men ages 18-26 were assigned randomly to the expository, academic narrative, classic narrative, or comparison conditions. Outcome measures related to the persuasive effects of the messages were attitudes toward talking to healthcare providers about the HPV vaccine and receptiveness to the HPV vaccine. Outcome measures related to the persuasive mechanisms of expository messages were argument strength, source credibility, and emotional arousal. Outcome measures related to the persuasive mechanisms of narrative messages were perceived realism, transportation, identification, and emotional arousal. Hypotheses predicted that argument strength and source credibility would predict changes in knowledge, attitudes, and vaccine receptiveness in the expository condition, whereas perceived realism, transportation, and identification would predict similar changes in the narrative conditions. An additional hypothesis predicted that emotional arousal would affect the persuasion process differently in the expository and narrative conditions. Results indicated that transportation, identification, and emotional arousal were stronger in the narrative conditions, but these variables did not predict persuasive outcomes. Conversely, perceived realism and source credibility had unexpected persuasive effects in both expository and narrative conditions. Implications of the findings and directions for future research are discussed