In response to low influenza vaccination rates among health care workers, health officials have explored determinants of uptake and developed communication interventions. Key to these efforts is how workers seek and attend to vaccine information. We applied a model of risk information seeking and processing to survey 226 physicians and nurses at a large, urban hospital (response rate = 5.7%; cooperation rate = 91.5%). Our goals were to (1) apply the model to a new setting, audience, and issue and (2) explore novel concepts (e.g., source credibility and information usefulness) and moderating relationships among variables. Consistent with previous research, information subjective norms-perceived social pressure to remain informed about vaccination-were a strong predictor of information seeking and systematic processing. Neither source credibility nor information usefulness independently increased explained variance, although they moderated the relationship between norms and communication behavior. We discuss theoretical and practical implications of these findings.