Guided by Uncertainty Management Theory (UMT) (Brashers, 2001), the objective of this dissertation was to develop and test a model of the effects of contradictory health information on uncertainty and information seeking, dubbed therein as The Contradictory Health Information Processing (CHIP) Model. Three empirical studies were conducted to accomplish this objective. In the first investigation, the model of the effects of uncertainty-arousing nutrition information was developed and tested. Generic measures that can be used across a range of health topics were also developed for each of the CHIP model’s concepts. These measures enabled the three experiments that comprise this dissertation. In Study 2, a revised CHIP model and several moderators of the causal relations identified in Study 1 were tested in the nutrition context. Finally, Study 3 tested the most recent version of the CHIP model, but in the context of a completely different kind of health topic, consumer health product safety. This third study also tested the moderating role of health self-efficacy and cognitive outcome expectations for the purpose of assessing the relationship between threat emotions and information-seeking intentions. Overall, the findings from these three studies support the CHIP model.