Background: The efficacy of infliximab (IFX) for mucosal healing of patients with Crohn's disease (CD) is well known. But the difference of efficacy of IFX for small bowel lesions and colonic lesions is not established yet. Small bowel lesions are more liable to achieve stricture than colonic lesions, because small bowel is narrow. The evaluation the efficacy of IFX for small bowel lesion of patients with CD is important to make up the strategy for patients with CD by using IFX. Subjects and methods: We evaluated 51 CD cases that were treated by IFX with 2 more times infusion. We performed CE or DBE, conventional colonoscopy before the infusion of IFX and after 2 more times infusion of IFX, and we scored the findings of ileal and ileocolonic anastomotic lesions or colonic lesions separately (Gut 2006; 55: 842-847). Results: The improvement is 51.4% (18/35) for colonic lesions and 57.9% (11/19) for ileal and ileocolonic anastomotic lesions. The mucosal remission is 17.1% (6/35) for colonic lesions and 15.8% (3/19) for ileal and ileocolonic anastomotic lesions. Residual active longitudinal ulcers after treatments of IFX were 61.1% (11/18) for colonic lesions and 66.7% (2/3). There are no statistical difference between colonic lesions and ileal/ileocolonic anastomotic lesions. Conclusion: IFX seems to have same therapeutic potential for colonic and small bowel lesions. It is more difficult to detect the small bowel CD lesions by several imaging diagnosis or blood test analysis than colonic CD lesions. Small bowel CD lesions might be more suitable indication for top-down therapy of IFX.