Adenomatous polyps are the most common neoplastic findings discovered in people who undergo colorectal screening or who have a diagnostic work-up for symptoms. It was common practice in the 1970s for these patients to have annual follow-up surveillance examinations to detect additional new adenomas and missed synchronous adenomas. As a result of the National Polyp Study report in 1993, which showed clearly in a randomized design that the first postpolypectomy examination could be deferred for 3 years, guidelines published by a gastrointestinal consortium in 1997 recommended that the first follow-up surveillance take place 3 years after polypectomy for most patients. In 2003 these guidelines were updated and colonoscopy was recommended as the only follow-up examination, stratification at baseline into low risk and higher risk for subsequent adenomas was suggested. The 1997 and 2003 guidelines dealt with both screening and surveillance. However, it has become increasingly clear that postpolypectomy surveillance is now a large part of endoscopic practice, draining resources from screening and diagnosis. In addition, surveys have shown that a large proportion of endoscopists are conducting surveillance examinations at shorter intervals than recommended in the guidelines. In the present report, a careful analytic approach was designed to address all evidence available in the literature to delineate predictors of advanced pathology, both cancer and advanced adenomas, so that patients can be stratified more definitely at their baseline colonoscopy into those at lower risk or increased risk for a subsequent advanced neoplasia. People at increased risk have either 3 or more adenomas, high-grade dysplasia, villous features, or an adenoma 1 cm or larger in size. It is recommended that they have a 3-year follow-up colonoscopy. People at lower risk who have 1 or 2 small (<1 cm) tubular adenomas with no high-grade dysplasia can have a follow-up evaluation in 5-10 years, whereas people with hyperplastic polyps only should have a 10-year follow-up evaluation, as for average-risk people. There have been recent studies that have reported a significant number of missed cancers by colonoscopy. However, high-quality baseline colonoscopy with excellent patient preparation and adequate withdrawal time should minimize this and reduce clinicians concerns. These guidelines were developed jointly by the US Multi-Society Task Force on Colorectal Cancer and the American Cancer Society to provide a broader consensus and thereby increase the use of the recommendations by endoscopists. The adoption of these guidelines nationally can have a dramatic impact on shifting available resources from intensive surveillance to screening. It has been shown that the first screening colonoscopy and polypectomy produces the greatest effects on reducing the incidence of colorectal cancer in patients with adenomatous polyps.