BACKGROUND: Wireless capsule endoscopy (WCE) offers endoscopic access to the small bowel and may therefore change diagnostic and therapeutic strategies in small bowel diseases. AIM: The aim of this prospective study was to validate the gain in information and therapeutic impact of WCE in patients with Crohn's disease. METHODS: Fifty six consecutive patients with Crohn's disease underwent computed tomography (CT) enteroclysis, and if stenoses <10 mm were excluded, WCE was carried out. RESULTS: In 15 patients (27%), WCE could not be performed due to strictures detected by CT enteroclysis. From the other 41 patients, jejunal or ileal lesions were found in 25 patients by WCE compared with 12 by CT enteroclysis (p=0.004). This gain in information was mainly due to detection of small mucosal lesions such as villous denudation, aphthoid ulcerations, or erosions. Both methods were not significantly different in the detection of lesions in the terminal/neoterminal ileum (WCE 24 patients, CT enteroclysis 20 patients). Therapy was changed due to WCE findings in 10 patients. Consecutively, all of them improved clinically. CONCLUSIONS: Capsule endoscopy improves the diagnosis of small bowel Crohn's disease. This may have significant therapeutic impact.