The association of Sweet's syndrome and Crohn's disease is rare. We report a new case of such association. A 45 year-old woman developed a diarrhea, fever, and skin lesions consistent with a presumptive diagnosis of Sweet's syndrome. Crohn's disease was also diagnosed. Oral prednisone, associated with mesalazine, effected improvement of both cutaneous lesions and bowel disease. The ten cases of the literature and ours show that Sweet's syndrome may occur during an acute phase of Crohn's disease. Most of the time, Crohn's disease has already been diagnosed. However, this was not so with our patient, wherein lies the originality of our case. A general corticotherapy is the preferred course of treatment.