Given the significant burden of cancer on contemporary morbidity and mortality, it is essential to assess public opinions, perceptions, and attitudes regarding the various risk factors for cancer. This is the objective of this review, based on data from the Cancer Barometer, a survey conducted in 2005 among 4,046 people representative of the French population aged 16 and older. Cancer is considered the most serious disease by the French, far ahead of AIDS and cardiovascular diseases. For major risk factors such as sun exposure, alcohol consumption, or smoking, the carcinogenic risk is known to almost everyone, but this consensus often masks deeply held beliefs that downplay this risk. These beliefs can lead to behaviors that are harmful to long-term health. Furthermore, the proliferation of perceived risks can also trigger or reinforce a form of risk denial. The prevalence of beliefs that downplay the cancer risk calls for continued efforts to guide the public toward preventive practices and to limit the isolation and stigmatization that people with cancer sometimes experience.[author’s abstract]