Bladder cancer represents 8% of all malignancies diagnosed in men and 3% in women. The risk factors for developing bladder cancer, including the incidence rate, morbidity, and mortality, vary according to the ethnic group, exposition rate at work, age, gender, and tobacco consumption. Moreover, there is a risk of developing this carcinoma due to dietary conditions, demonstrating that certain enzymes neutralize oxidative compound derivative of carcinogens, which if not degraded, accumulate in the body and destroy epithelial cells of the bladder, causing an increase in the risk of developing this disease. The detoxifying enzymes inactivate dangerous chemical compounds and anions for the cell; that is, why it is important to know if the polymorphisms pro198leu in GPX-1 and ile58thr in MnSOD are associated with bladder cancer. In this study, 120 individuals were analyzed as controls and 97 individuals with previously diagnosed bladder cancer. In the case of polymorphism pro198leu, highly significant differences were observed and individuals with this polymorphism presented a probability of developing bladder cancer 3.8 times greater than controls (OR = 3.8; 95% CI 2.16-6.78; p < 0.001). No significant differences in polymorphism ile58thr of MnSOD gene occurred when we compared the study population (OR = 2.1; 95% CI 1.26-3.49; p > 0.05). The results indicate that polymorphism of GPX-1 gene influences the risk of developing bladder cancer in the Ecuadorian population, suggesting that more research on detoxifying genes in bladder cancer should be conducted.