Objectives: This study aims to examine associations between the perceived ambiguity about cancer prevention recommendations with perceived cancer risk and cancer prevention behaviors. Methods: Participants for this study were 1,000 men and women aged 20-69 years. We performed logistic regression analyses to test the effects of ambiguity on perceived cancer risk and cancer prevention behaviors. Results: Perceived ambiguity was positively related with perceived cancer risk and drinking, and was inversely associated with consumption of fruits and vegetables and avoiding salty or burnt foods. Conclusions: These findings suggest that perceived ambiguity about cancer prevention recommendations may have broad and important effects on other health cognitions and behaviors, and we discuss the implications of these findings for future cancer communication efforts.