We encountered a case of Cronkhite-Canada syndrome in which contrast radiologic examinations of the upper and lower digestive tract were performed immediately before and after the development of the clinical symptoms. These contrast radiologic images showed mainly mucosal coarseness and no polyposis of the stomach and colon. The endoscopy, performed 3 months later from the development of the clinical symptoms, revealed polyposis of the stomach and colon. So we recognized that the clinical symptoms developed before appearance of the polyposis of the digestive tract and the polyposis progressed rapidly.