Bladder cancer is one of the most common cancers in the world. Studies have shown that genetic factors may play important roles in the development of this disease. Interleukin-2 (IL-2) is a cytokine involved in the regulation of proliferation and functional activities of T- and NK-cell. Recombinant IL-2 has been shown to be a promising agent for the activation of immune response against tumors. The aim of this study was to examine the effect of -330T/G polymorphism of the IL-2 gene on the development of bladder cancer in the Chinese population. IL-2 -330T/G polymorphism was detected by polymerase chain reaction-restriction fragment length polymorphism in 365 bladder cancer cases and 390 age-matched healthy controls. Data were analyzed using the Chi-square test. Results showed that individuals with TG genotype or GG genotype had significantly increased susceptibility to bladder cancer (odds ratio [OR]=1.48, 95% confidence interval [CI]: 1.08-2.02, p=0.014 and OR=2.22, 95%CI: 1.35-3.68, p=0.002). Also, the frequency of the G allele was significantly higher in bladder cancer cases compared with healthy controls (OR=1.40, 95%CI: 1.14-1.73, p=0.002). In conclusion, IL-2 -330T/G polymorphism may be involved in the etiology of bladder in Chinese population.