AIM: To analyse the impact of NOD2/CARD15 mutations on the clinical course of Crohns disease patients from an eastern European country (Hungary).METHODS: We investigated the prevalence of the three common NOD2/CARD15 mutations (Arg702Trp, Gly908Arg,1007finsC) in 148 patients with Crohns disease, 128patients with ulcerative colitis and 208 controls recruited from the University of Szeged, Hungary. In patients with Crohns disease, the prevalence of NOD2/CARD15 mutations was correlated to the demographical and clinical parameters.RESULTS: In total, 32.4% of Crohns disease patients carried at least one mutant allele within NOD2/CARD15compared to 13.2% of patients with ulcerative colitis (P = 0.0002) and to 11.5% of controls (P＜0.0001). In Crohns disease patients, the allele frequencies for Arg702Trp,Gly908Arg and 1007finsC were 7.1%, 3.0% and 10.8%respectively. Interestingly, only the 1007finsC mutation was associated with a distinct clinical phenotype. The patients positive for the 1007finsC mutation suffered more frequently from stenotic disease behaviour (P = 0.008). Furthermore,51.9% of patients positive for the 1007finsC mutation underwent a surgical resection within the ileum compared to only 17.4% of patients without the 1007finsC mutation (P = 0.001). With respect to the other two mutations (Arg702Trp and Gly908Arg), no associations were found with all investigated clinical parameters.CONCLUSION: NOD2/CARD15 mutations are frequently found in Crohns disease patients from Hungary. The 1007finsC mutation is associated with stenotic disease behaviour and frequent ileal resections.