Informed by the Situational Theory of Problem Solving (STOPS), this study used data from the Health Information National Trends Survey, a large and representative national sample, to examine predictors of information seeking and information accessing of health information, including cancer-related information. We found that the independent variables in STOPS-problem recognition, involvement recognition, and referent criterion- well predicted people's information seeking of cancer-related information and accessing of health information on line. However, the impact of trust in online health information was more complicated than anticipated. Our study demonstrated the utility of the STOPS in the health information context. Theoretical and practical implications are discussed.