Objective: Self-affirmation reduces defensive responses to threatening health information, but little is known about the cognitive processes instigated by self-affirmation. This study tested whether self-affirmation increases responsiveness to threatening health information at the implicit level. Design: In an experimental study (N = 84), the authors presented high- (coffee drinkers) and low-relevance (noncoffee drinkers) participants with threatening health information linking caffeine consumption to health problems. Prior to reading this information, the authors manipulated self-affirmation. Main Outcome Measures: Participants completed an unobtrusive lexical decision task to measure the accessibility of threat-related cognitions and reported their perceptions of message quality and intentions to take precautions. Results: Among high-relevance participants, self-affirmation increased the accessibility of threat-related cognitions, increased perceptions of message quality, and promoted adaptive behavioral intentions. Conclusion: The findings suggest that self-affirmation can increase implicit responsiveness to threatening health information among a target audience, that is, people for whom the health information is highly relevant. © 2009 American Psychological Association.