To assess whether polymorphisms of the interleukin-23 receptor (IL23R) gene are associated with bladder transitional cell carcinoma because chronic inflammation contributes to bladder cancer and the IL23R is known to be critically involved in the carcinogenesis of various malignant tumors. 226 patients with bladder cancer and 270 age-matched controls were involved in the study. Polymerase chain reaction-restriction fragment length polymorphism was used for genotyping. Genotype distribution and allelic frequencies between patients and controls were compared. In all three single nucleotide polymorphisms of IL23R studied, the distribution of genotype and allele frequencies of rs10889677 differed significantly between patients and controls. The frequency of allele C of rs10889677 was significantly increased in cases compared with controls (0.2898 vs. 0.1833, odds ratio 1.818, 95 % confidence interval 1.349-2.449). The result indicates that IL23R may play an important role in the susceptibility of bladder cancer in Chinese population.