The aim of the present study was to determine whether endothelial nitric oxide synthase (eNOS) genepolymorphisms play a role in development of bladder cancer in the Turkish population. The study was performedon 75 patients (64 men, 11 women) with bladder cancer and 143 healthy individuals (107 men, 36 women) withany kind of cancer history. Three eNOS gene polymorphisms (T-786C promoter region, G894T and intron 4VNTR 4a/b) were determined with polymerase chain reaction and restriction fragment lenght polymorphismmethods. In our study, GT and TT genotypes for eNOS G894T polymorphism were found to significantly varyamong patients with bladder cancer and control group (OR: 0.185, CI: 0.078-0.439, p=0.0001 and OR: 0.324,CI: 0.106-0.990, p=0.026). Also, the frequency of the 894T allele was significantly higher in patients with bladdercancer (51%). No association was identified for eNOS T-786C and intron 4 VNTR 4a/b polymorphisms betweenpatients with bladder cancer and control groups in our Turkish population.