Polyposis syndrome is one of the important target of enteroscopy. Neoplastic polyp is treated as a precancerous lesion. In contrast to the stomach and colon, the lumen diameter of small intestine is small. Therefore, polyp is treated for avoiding intussusception. As for surveillance, capsule endoscopy (CE), device assisted endoscopy (DAE), and MR enterography (MRE) are used. CE is used for detailed observation of mucosa. MRE is less sensitive for diminutive polyps, but position and size of lesions can be detected accurately. DAE is used for detailed observation of mucosa and treatment of lesions. Familial adenomatosis polyposis syndrome (FAP) is a heredity cancer syndrome. Not only the colon, small intestine is also affected. Spigelman staging system is used for risk stratification. High risk group patients need to be surveyed by CE or MRE. Enteroscopy can be considered for therapeutic intent in patients with positive findings. Ileal pouch should be also examined, because there is an increased risk of adenomas in the ileum after colectomy. Peutz-Jeghers (PJ) syndrome is a heredity hamartomatous polyposis. Guidelines recommend that surveillance for small intestine is started at age eight years. Small bowel polyps greater than 15 mm in size should be resected. Multiple polyps are difficult to retrieved. Small PJ polyps are not neoplasia. Therefore, clipping or ligation using a detachable snare are applicable. Cronkhite-Canada Syndrome is a non-neoplastic polyposis of gastrointestinal tract. Small intestine is also affected. Cancer risk is low and polyps disappear when treatment is effective. Progress of modalities enables better management of polyposis.