This research examines the influence of norm-based messages (positively worded descriptive vs. negatively worded descriptive vs. injunctive vs. basic information) on intentions and risk perceptions about receiving human papillomavirus (HPV) vaccination among young adults aged 18-29. Results from an experiment show that compared to the basic information condition, additional exposure to injunctive normative messages increased intention to seek further information about HPV vaccination, which in turn enhanced intention to get the vaccine. Negatively worded descriptive normative messaging should be used with caution since it resulted in the highest risk perceptions of the HPV vaccine, compared to positively worded descriptive norms and basic information messages. Theoretical and practical implications are further discussed.