Three new cases of small intestinal adenocarcinoma complicating Crohn's disease are reported. Seventy‐five other cases have been reported to date. Analysis of these cases in comparison with de novo adenocarcinoma of the small bowel shows that they: (1) occur at a younger age; (2) occur in distal small bowel; (3) show a male predilection; and (4) have a worse prognosis. The increasing number of these cases suggests that small intestinal regional enteritis predisposes to adenocarcinoma. Improved prognosis can only be achieved with earlier diagnosis.