Two hundred and three patients with Crohn's disease seen at our clinics and affiliated centers from April 1973 to August 1988 were followed for 4.4 +/- 3.2 years (mean +/- SD), in order to evaluate the prognosis of Crohn's disease in Japan. These 203 patients (142 males and 61 females) fulfilled the following criteria; 1) they have been followed at the outpatients clinic for more than six months or 2) they have been admitted to us for more than a month. Of these, 83 (40.9%) had ileitis, 60 (29.6%) ileocolitis, 25 (12.3%) colitis, 15 (7.5%) miscellaneous types and the remaining 20 (9.9%) had undergone bowel resection. Cumulative survival rate and cumulative probability of surgery were calculated by life table method. Cumulative survival rate in these patients was compared with expected survival rate of sex and age matched general population. Cumulative survival rates five and ten years after diagnosis were 98.9% and 98.9%, respectively. There were no significant differences in the survival rates between two groups. Cumulative probability of surgery five and ten years after onset of symptoms were 16.2% and 39.1%, respectively. Cumulative probability of surgery five and ten years after diagnosis were 25.9% and 46.9%, respectively. From these results, the prognosis of Japanese patients with Crohn's disease appears to superior to that in European and American literatures.