Gastric cancer is a multifactorial disease with the involvement of both genetic and environmental risk factors. Genetic variation in genes encoding cytokines and their receptors determine the intensity of the inflammatory response, which may contribute to individual differences in the outcome and severity of the disease. Transforming growth factor (TGF-β) signaling pathway plays an important role in the genesis and progression of tumors through regulating cell proliferation and differentiation. A hospital-based case-control study was conducted to investigate whether TGF-β1 -509 C/T polymorphism can modify the risk of gastric cancer. Seventy endoscopically and histopathologically confirmed gastric cancer patients and 100 age and sex-matched healthy controls were enrolled in the case-control study. TGF-β1 -509 C/T gene polymorphism was carried out by amplification refractory mutation system polymerase chain reaction (ARMS-PCR) method followed by agarose gel electrophoresis. Statistical analysis was applied to test for the significance of the results. The distribution of TGF-β1 genotypes at -509 C/T were CC 37.14%, CT 50%, and TT 12.86% in gastric cancer patients and CC 52%, CT 42%, and TT 6% in control subjects. The allelic frequencies of C and T were 0.621 and 0.379 in gastric cancer patients and 0.73 and 0.27 in control subjects, respectively. Our study imply that T allele of TGF-β1 -509 C/T genotypes may be a risk factor of genetic susceptibility to gastric cancer in south Indian population.