The aim of this study was to evaluate the accuracy of multidetector CT in patients with Crohn's disease (CD) relapse after ileocolic resection compared with endoscopy. Thirty-four patients were studied by endoscopy and multidetector CT, after oral administration of polyethylene glycol solution (n = 21) or after administration of methylcellulose via nasojejunal tube (n = 13). In CT examinations we evaluated the presence of mural thickening, target sign, perienteric stranding, comb sign, fibrofatty proliferation and complications. Endoscopic results were classified in accordance with Rutgeerts score (from 0 to 4). The statistical evaluations were carried out by using Fisher's exact text and chi (2) testing (p < 0.05, statistically significant difference). Sensitivity, specificity and accuracy of the CT were 96.9%, 100% and 97%, respectively. We found a statistically significant correlation between an endoscopic score of 4 and the CT signs of target sign, perienteric stranding, comb sign and fibrofatty proliferation, and between scores 1 and 2 and mucosal hyperdensity without or with mural thickening, respectively (p < 0.05). Moreover, only CT identified the presence of jejunal and proximal ileum disease in two and three patients, respectively, and fistulas in three patients. CT is a reliable method in the diagnosis of CD relapse and shows agreement with the approved endoscopic Rutgeerts score.