The pathogenesis of inflammatory bowel disease (IBD)is only partially understood. Various environmental and host (e.g. genetic-, epithelial-, immune and nonimmune) factors are involved. It is a multifactorial polygenic disease with probable genetic heterogeneity.Some genes are associated with IBD itself, while others increase the risk of ulcerative colitis (UC) or Crohn's disease (CD) or are associated with disease location and/or behaviour. This review addresses recent advances in the genetics of IBD. The article discusses the current information on the crosstalk between microbial and genetic factors (e.g. NOD2/CARD15, SLC22A46A5 and DLG5). The genetic data acquired in recent years help in understanding the pathogenesis of IBD and can identify a number of potential targets for therapeutic intervention.In the future, genetics may help more accurately diagnose and predict disease course in IBD.