It has long been known that Crohn's disease may occur in association with certain forms of malignancy, specifically adenocarcinoma and lymphoma of the bowel and carcinoma of the vulva and perianal area. Here, the authors report the rare occurrence of extraintestinal Hodgkin's disease in a patient with documented regional enteritis of five years' duration. They propose explanations for this unusual combination of disease, reported in the literature only once previously, and review the pathophysiology of lymphoma and regional enteritis.