Risk perceptions and worry are important constructs in many theoretical frameworks used to develop cancer screening interventions. Because most cancers for which we have early detection or prevention strategies are gender specific, few investigations have examined gender differences. We examined gender differences in the magnitude of, and associations with, perceived risk and worry by cancer type. Our sample included 939 men and 1,580 women >or= 50 years old with no history of relevant cancers from the 2003 Health Information National Trends Survey (HINTS). Dependent variables included absolute and comparative perceived risk and worry for gender-specific (breast/prostate) and colon cancers. We examined demographics, health status, health behaviors, cancer beliefs, and cancer communication variables as correlates. Linear regression analyses and pairwise contrasts were conducted with SUDAAN. Men reported greater comparative perceived risk for developing cancers, whereas women reported more frequent cancer worry. For both genders, perceived risk and worry were lowest for colon cancer. Correlates of perceived risk and worry varied, and several associations were moderated by gender. Different risk messages and intervention strategies may be needed to influence males' and females' perceived cancer risk and worry. All effect sizes were small, and future prospective research is needed to confirm our findings.