Risk factors analysis in bladder cancer should consider not only the clinical and pathological features of the tumor but also environmental and lifestyle factors. They may play, in fact, a relevant role not only in the pathogenesis but also in the biological behavior of the tumor. The association between cigarette smoking and bladder cancer has been consistently confirmed in several case-control and cohort studies. The risk of bladder cancer seems to increase with duration and intensity of smoking. Another environmental risk factor, although not definitively proved, is water supply. Chlorination or water pollution by pesticides and other chemical factors is considered a relevant risk factor. Familiarity and genetic predisposition, diet and individual risk factors should be taken into account.