This study used data from the 2005 Health Information National Trends Survey, a national sample of U.S. households (N = 5,586), to (1) explore the extent to which specific sources of health information are associated with certain beliefs about cancer; and (2) examine whether the relationship between health information sources and beliefs about cancer is moderated by psychological distress. Health information on the local news was associated with greater ambiguity about cancer prevention recommendations (OR 1.22, 95% CI 1.02-1.46, p < .05), while less ambiguity was associated with cancer-specific information (OR 0.81, 95% CI 0.69-0.94, p < .05), health information in the newspaper (OR 0.82, 95% CI 0.69-0.97, p < .05), and health information on the Internet (OR 0.71, 95% CI 0.61-0.84, p < .001). Health information on the local news was also associated with lower likelihood of higher perceived relative risk of cancer (OR 0.67, 95% CI 0.52-0.86, p < .01). No source of information was associated with the belief that cancer is primarily caused by behavior/lifestyle factors. Psychological distress greatly increased the optimistic bias of those who read health information in the news (OR 3.68, 95% CI 1.69-8.03, p < .001) but had no other moderating effect. Findings suggest that information seeking using active channels of health information decreases ambiguity and corrects for optimistic bias.