Helicobacter pylon infection is strongly associated with gastric cancer. In the present study, the relationship between interleukin-1B (IL-1B) polymorphism, H. pylori infection, and prevalence of gastric cancer (CC) in patients of North India was evaluated using genomic DNA directly extracted from biopsy tissues for performing PCR-RFLP. A total of 136 CC cases and I 10 healthy controls were included for studying polymorphisms in the genotypes of IL-1B-511, -31, +3954 and IL-1RN both in the presence and absence of H. pylori active infection. Results showed that the frequency of IL-1RN 2/2 was significantly higher in CC cases (21.32%) than the controls (9.09%) with an odds ratio (OR) of 4.391 (95% CI 1.093-10.131). The risk of GC was also found higher in other genotypes of IL-1B namely, -511 TT (chi(2) = 18.975, p < 0.001), -31CC (chi(2) = 21.219, p<0.001), +3954 CT (chi(2)=21.082, p<0.001) and IL-1RN 1/2 (chi(2) = 30.543, p<0.001) with active infection of H. pylori. Our findings indicate that the IL-1B and IL-IRN polymorphisms are associated with the development of CC and H. pylori infection markedly increases the risk of CC in North Indian population. Additionally, IL-1B-511 C/C and IL-RN 2/2 polymorphisms seem to be involved in the development of GC in H. pylori uninfected patients. (C) 2009 Elsevier Inc. All rights reserved.