Multiple factors are incriminated in the etiopathogeny of necrotizing enterocolitis (NEC) in premature infants, including oral feeding, vascular abnormalities, increase in pro-inflammatory cytokines, and inappropriate response of the intestinal barrier to bacterial microflora. CARD15/NOD2 is a gene recently recognized as important in the innate response to gut flora and is involved in Crohn's disease susceptibility. We thus tested its putative role in NEC. Ten children (seven boys and three girls) suffering from NEC who were admitted to Robert Debré hospital between 1999 and 2002 were retrospectively included in the study. Genetic screening of the 11 constant exons and the exon-intron junctions of CARD15/NOD2 by direct sequencing revealed no novel mutations of that gene in NEC patients. Furthermore, the three main mutations of CARD15/NOD2 (R702W, G908R, and 1007fs) associated with susceptibility to Crohn's disease were not found in these patients. Our results suggest that CARD15/NOD2 does not play a major role in genetic susceptibility to NEC.