We describe two families in which some members are affected by familial polyposis syndrome: in one family a case of ulcerative colitis and in the other a case of Crohn's disease were found. This is the first report about this family association, but in our opinion the fact that two cases have been found in one series suggests that this association could be more frequent than reported so far. The research for a genetic pattern of inflammatory bowel disease could be addressed towards chromosome 5.