Crohn's disease and diverticulitis of the sigmoid may be combined in old patients, this association could lead to difficulties in diagnosis and treatment. Three cases of Crohn's colitis associated with diverticula, two females and one male, aged between 66 and 80 years are reported by the authors. In a review of the literature, some clinical, radiological and endoscopic findings may suggest the diagnosis, which guides subsequent treatment. A high morbidity is observed after surgery. In our series, sigmoidectomy cured both Crohn's colitis and diverticulitis.