Many states and sports leagues are instituting concussion policies aimed at reducing risk of morbidity and mortality; many include mandates about the provision of concussion education to youth athletes. However, there is limited evidence if educational materials provided under these typically vague mandates are in fact effective in changing concussion risk-related behavior or any cognition predictive of risk-related behavior. The purpose of this pilot randomized controlled study was to conduct a theory-driven evaluation of three publically available concussion education materials: two videos and one informational handout. Participants were 256 late adolescent males from 12 teams in a single league of ice hockey competition in the United States. Randomization of educational condition occurred at the team level. Written surveys assessing postimpact symptom reporting behavior, concussion knowledge, and concussion reporting cognitions were completed by participants immediately before receiving their educational intervention, 1 day after, and 1 month after. Results indicated no change in any measure over any time interval, with the exception of perceived underreporting norms. In one of the video conditions, perceived underreporting norms increased significantly 1 day after viewing the video. Possible content and viewing environment-related reasons for this increase are discussed. Across all conditions, perceived underreporting norms increased 1 month after intervention receipt, raising the possibility that late in the competitive season underreporting may be perceived as normative. The need for the development of theory-driven concussion education materials, drawing on best practices from health behavior scholars, is discussed.