Thus, the aim of this study was to evaluate whether NOS2 polymorphisms Ser608Leu in exon 16 and -954G/C and -1173C/T, both in the promoter region, are associated with risk of chronic gastritis and gastric cancer in a Brazilian population and whether there is an association of cancer with risk factors such as smoking, alcohol intake and H. pylori infection. This evidence concerns the gene NOS2 and gastric cancer.