Background: Urinary bladder cancer is the third leading cancer in male in Turkey. The incidence rates of bladdercancer are 13.0 and 2.1/ 100,000 for males and females, respectively, in Turkey. Smoking and occupation are themain causes of urinary bladder cancer. Our goal was to investigate the etiologic factors of urinary bladder cancer inour region to improve our preventive services. Methods: We conducted a hospital-based case-control study of patientswith bladder cancer and of controls drawn randomly from the acute non–urinary patients of three hospitals inIstanbul. Controls were matched for age, sex, and residence. Results: We interviewed 290 cases and 580 controls.Smoking and occupation were found to be related factors in urinary bladder cancer. Conclusion: Preventive measuresshould be planned regarding smoking and occupational factors for urinary bladder cancer in Turkey.