The aim of the present study is to clarify the point of surgical treatment for intestinal and anal lesions in patients with Crohn's disease. We classified 64 patients with Crohn's disease into two groups; 24 patients undergone abdominal operation and 40 patients without operation. Both groups were compared for some clinical factors, QOL, and means of medical therapy. And we also studied peri-anal lesions which are commonly accompanied with the patients with Crohn's disease. There were no significant differences in onset-age of the disease and sex ratio between two groups. The mean interval between the onset of the disease and operation was about four years. The operative rates in small intestinal type (45%) and small-large intestinal type (40%) were larger than in large bowel type (15%). Bowel resection or strictureplasty was performed because of stenosis or perforation of the intestine. Operative complications were reported in only three patients, and all had improved by conservative therapy. The QOL after operation was significantly better than before operation (admission number, IOIBD score, medical therapy's menu). Exscerbation of the disease occurred in seven patients who needed re-operation. Anal lesions were reported in 42 patients. Of these 42 patients, 22 patients underwent surgical treatment and had good results. Remaining 20 patients had spontaneous remission after the treatment for abdominal lesions. We think that the time of surgical therapy should be decided in terms of improving QOL in patients with Crohn's disease.