A well documented case of a patient with both Crohn's disease and ulcerative colitis is presented. A 29 year old woman underwent resection of her terminal ileum and ascending colon for typical Crohn's disease with ileocolitis. Eleven years later, an ileoproctocolectomy was performed for typical ulcerative colitis involving the left colon. The resection specimen also showed evidence of colonic Crohn's disease near the anastomotic site. This unusual case shows that Crohn's disease and ulcerative colitis can occur in the same patient. The rarity of such cases supports the concept that Crohn's disease and ulcerative colitis are separate entities, rather than different manifestations of the same disease process.