Background and study aims: To summarize the published literature on assessment of appro-priateness of colonoscopy for screening for colorectal cancer (CRC) in asymptomatic individuals with-out personal history of CRC or polyps, and -report -appropriateness criteria developed by an expert panel, the 2008 European Panel on the Appro-pri-ate-ness of Gastrointestinal Endoscopy, EPAGEII. Methods: A systematic search of guidelines, sys-tem-atic reviews, and primary studies regarding -colonoscopy for screening for colorectal cancer was performed. The RAND/UCLA Appropriateness Method was applied to develop appropriateness criteria for colonoscopy in these circumstances. Results: Available evidence for CRC screening -comes from small case-controlled studies, with -heterogeneous results, and from indirect evidence from randomized controlled trials (RCTs) on fecal occult blood test (FOBT) screening and studies on flexible sigmoidoscopy screening. Most guidelines recommend screening colonoscopy every 10years starting at age 50in average-risk individuals. In individuals with a higher risk of CRC due to family history, there is a consensus that it is appropriate to offer screening colonos-copy at<50years. EPAGEII considered screening colonoscopy appropriate above 50years in aver-age-risk individuals. Panelists deemed screening colonoscopy appropriate for younger patients, with shorter surveillance intervals, where family or personal risk of colorectal cancer is higher. A positive FOBT or the discovery of adenomas at -sigmoidoscopy are considered appropriate indications. Conclusions: Despite the lack of evidence based on randomized controlled trials (RCTs), colo-noscopy is recommended by most published guide-lines and EPAGEII criteria available online (http: //www.epage.ch), as a screening option for CRC in individ-uals at average risk of CRC, and undisputedly as the main screen-ing tool for CRC in individuals at moderate and high risk of CRC.