Ulcerative colitis (UC) is a chronic condition of unknown etiology and a polygenic disease. The interleukin 27 (IL-27) have been implicated in the pathogenesis of several autoimmune diseases including inflammatory bowel disease. Several polymorphisms of IL-27 have been associated with several types of cancer and immune disorders. The aim of the present study was to evaluate the association between IL-27 gene polymorphisms and the development of UC. Four polymorphisms of IL-27p28 gene (rs181206, rs26528, rs17855750, and rs40837) and three of the Epstein-Barr virus-induced gene 3 (EBI3) (rs428253, rs4740, and rs4905) were genotyped by 5' exonuclease TaqMan genotyping assays on an ABI Prism 7900HT Fast Real-Time PCR System in 375 Mexican patients with UC and 1599 Mexican Mestizo healthy unrelated individuals. IL-27 levels were determined in 458 healthy controls. Under recessive model adjusted by age and gender, the IL-27p28 rs17855750 polymorphism was associated with decreased risk of developing UC (OR=0.27, 95% CI: 0.06-1.13, P=0.031). On the other hand, under recessive models adjusted by age and gender, the EBI3 rs428253 (OR=0.54, 95% CI: 0.29-0.99, P=0.035), rs4740 (OR=0.60, 95% CI: 0.36-1.01, P=0.046) and rs4905 (OR=0.59, 95% CI: 0.35-1.01, P=0.043) were associated with decreased risk of developing UC. Similar levels of IL-27 were observed among the genotypes of the studied polymorphisms. IL-27 polymorphisms might play a protective role for the development of UC in the Mexican population.