Recent guidelines on postpolypectomy surveillance have focused on identifying patients with adenomas who are at high risk for development of significant neoplasms (cancer or "advanced adenoma") after clearing colonoscopy and should undergo frequent follow-up examinations and those at low risk who require infrequent follow-up examinations. This article reviews the guideline recommendations from the American College of Gastroenterology, American Gastroenterological Association consortium, and the American Cancer Society, and discusses the rationale for the recommended intervals of colonoscopic examinations in low and high-risk postpolypectomy patients. When colorectal cancer is identified, the initial colonoscopic goal in the peri-operative period is to clear the colon of synchronous neoplasms. After this is accomplished, the goal shifts to performance of colonoscopy at intervals that are appropriate for prevention and early detection of second cancers. These intervals often approximate those used in postpolypectomy surveillance. An exception to this approach is patients with rectal cancer operated by traditional blunt dissection techniques, for which there is a rationale for interval flexible sigmoidoscopy and/or rectal ultrasound to look for local recurrences.