Genetic factors play a significant role in determining inflammatory bowel disease (IBD) susceptibility. Epidemiologic data support genetic contribution to the pathogenesis of IBD, which include familial aggregation, twin studies, and racial and ethnic differences in disease prevalence. Recently, several new genes have been identified to be involved in the genetic susceptibility to IBD. The characterization of novel genes potentially will lead to the identification of therapeutic agents and clinical assessment of phenotype and prognosis in patients with IBD. The development of genetic markers associated with clinical outcomes in patients with IBD will be very important in the future. The progress of molecular biology tools (microarrays, proteomics, and epigenetics) have progressed the field of the genetic markers discovery. The advances in bioinformatics coupled with cross-disciplinary collaborations have greatly enhanced our ability to retrieve, characterize, and analyze large amounts of data generated by the technological advances. The techniques available for markers development are genomics (single nucleotide polymorphism genotyping, pharmacogenetics, and gene expression analyses) and proteomics. This could be a potential great benefit in predicting the course of disease in individual patients and in guiding appropriate medical therapy.