Epidemiological evidence indicates that obesity plays an important role in cancer incidence. A telephone survey of 1,433 adults, aged 18+ years who reported their knowledge and beliefs regarding behavioral risk factors for cancer, was conducted. Most respondents believed that people can take steps to reduce cancer risk; however, many, particularly obese respondents, did not rate being overweight as a very important risk factor. A dedicated public education campaign focused on overweight and cancer is needed to address the significant gap in knowledge about the role of weight control in preventing cancer, particularly among those most afflicted.