IntroductionThe p53 gene is frequently mutated in various forms of human cancers. The p53 signaling pathway isactivated by endogenous and exogenous stress signals and induces growth arrest, cellular senescenceand apoptosis. A common polymorphism occurs at codon 72 of the p53 has been demonstrated that itmight be associated with bladder cancer risk. However, results of researches related to this topic werecontroversial and more investigations and samples size needed.GoalTo evaluate TP53 Arg72Pro polymorphism in Mongolian patients with bladder cancer.Materials and MethodWe evaluated TP53 Arg72Pro polymorphism in DNA samples from 82 patients with bladder cancerand 82 age and gender matched healthy subjects using polymerase chain reaction-based restrictionfragment length polymorphism. All enrolments of this study were Mongolians. The association betweeneach genotype of TP53 Arg72Pro and bladder cancer risk was examined by the odds ratio and 95%confi dence interval, using logistic regression analysis. The early age onset of bladder cancer patientswas also evaluated among different genotypes of TP53 Arg72Pro.ResultsThe proportion of the polymorphism of TP53 Arg72Pro were RR 53.7% (n=44); PR 34.1% (n=28); andPP 12.2% (n=10) in the bladder cancer patients, whereas RR 52.4% (n=43); PR 28% (n=23); and PP19.6% (n=16) in healthy controls. The PR genotype increased the risk of bladder cancer (OR1.189;95% CI 0.42-0.75; p=0.997) in Mongolian people, whereas PP genotype protected from the cancer(OR=0.610; 95% CI 0.22-0.44, p=0.998) compared to the RR, respectively, however signifi cance isweak. Moreover, there was no association between each genotype of TP53 Arg72Pro (RR=52; PR=54;PP=58) and early onset of bladder cancer in the Mongolian population.Conclusion: Our result indicates that the PR genotype tends to increase the risk of bladder canceramong Mongolians. RR genotype of TP53 Arg72Pro is more prevalent among Mongolians.