Polyposis of the colon is a colon cancer predisposition syndrome. Familial adenomatous polyposis (FAP) accounts for 1% of the cases of inherited colorectal cancer (CRC). The National Register of inherited CRC and polyposis of the intestines keeps track of 18 patients from 14 families with FAP. Eight of them have been operated of CRC, on 6 patients preventive colectomy with ileorectal anastomosis has been done and four patients refused surgery. Colectomy has been done due to the malignant development also on a female patient with difused juvenile polyposis with adenomatosis. Of three patients under surveillance with the Peutz-Jeghers syndrome, surgery has been done on one female patient with ileus and bleeding large polyps.