Introduction: Bladder cancer is one of the most common diseases treated by urologists and most of them are transitional cell carcinomas. In men, it is the fourth most common cancer after prostate, lung and colorectal cancer. It is the eighth most common cancer, accounting for 2.3% of all cancers in women. The relationship between smoking and transitional cell carcinoma (TCCa) of the bladder is well known. It is established that patients with TCCa who smoke cigarettes have worse prognosis then who don't smoke. Materials and Methods: To show the relation between smoking and TCCa, we correlated the smoking habits of the cases with TCCa and the control group who doesn't have the disease. We also evaluated the disease prognosis of the quitters and the continued smokers. Results: We evaluated the medical records of 249 cases having transitional cell carcinoma between 1990 and 2001. Gender, ages, smoking habits and the presence of intravesical treatment of patients and stage, degree, the greatest dimension and multifocality of primary tumor was noted. The smoking rate of cases with TCCa and the control group consisted of 200 patients who doesn't have TCCa was 65.4% and 33% respectively. Superficial TCCa having 173 cases evaluated in 3 groups by smoking habits as non-smokers, quitters and continued smokers. The recurrence and progression rate of tumor evaluated. We found 63.5% recurrence free rate in 58 month of follow-up rate. This rate was 44.4% in young, 60.6% in males, 49.1% in cases with multifocal tumors and 57.5 % in cases who have bigger than 2.5 cm primary tumor and 48.1% within continued smokers. These rates were significantly and statistically lower than the others. The difference between tumor's stage and degree in three groups was not found statistically significant. Conclusion: The relation between the tobacco using and TCCa should be well explained to patients and the continued smokers should be follow up closely because of the high risk of recurrence.