Background: Avoiding health information is relatively common and is associated with lower knowledge of health risks and lower engagement in protective health behaviour. Health information avoidance likely limits the effectiveness of health communication interventions. Objective: To identify beliefs associated with avoiding health information. Design: Two cross-sectional studies. Setting: Two representative samples of adults residing in the USA. Method: We tested whether low health agency beliefs and low perceptions of threat underlie the tendency to avoid diabetes or colorectal cancer health information in two samples. Results: An exploratory factor analysis (EFA) of our variables indicated that beliefs could be grouped into two sets of constructs that mapped onto agency (locus of control, fate) and two that mapped onto threat perception (dread, perceived risk). Information avoidance was common. In the two samples, 30% and 34% indicated they preferred to avoid information about diabetes and 20% and 19% indicated they preferred to avoid colorectal cancer information. Results were largely consistent across studies and diseases. In final adjusted regression models, beliefs indicating lower health agency were consistently associated with more avoidance. Some threat perception variables (worry about getting the disease and having a family history of the disease) were associated with less avoidance; absolute and comparative perceived risk were not. Conclusion: Given that health information avoidance likely undermines a wide range of health communication and self-regulation strategies, future health communication efforts might be advanced by developing intervention approaches that involve enhancing perceived control over health prior to delivering health messages.