Individuals typically overestimate survival for lung cancer and underestimate it for melanoma. However, reporting of results generally masks the extent of disagreement between people on survival rates. Most methods used to question individuals are of little use and are not comparable across studies. The topic of people’s perceptions of survival for various cancers is under-researched. A clearer definition is needed of survivability, as is a standard way to measure it and then present the information. We have undertaken a review of studies reporting public perceptions of cancer survival rates and compared the results, where possible, with actual survival rates. We also investigate some potential implications of people’s underestimation or overestimation of survival for screening and prevention behaviours and delineate implications for oncologists.