Bladder cancer is one of the most commonly diagnosed malignancies worldwide. It is the most common urological cancer; it comprises a significant part of urologists' work. The term bladder cancer is used to describe collectively tumors of urinary bladder urothelial origin which exhibit diverse biological behavior, ranging from relatively benign to highly malignant. Thus, bladder cancer can be without serious clinical consequences for the patient who has an isolated superficial bladder tumor, or it can be a lethal disease. Eighty per cent of bladder cancers are superficial at presentation in that they have not invaded into the muscle. The remaining 20% are muscle-invasive, which carry a much worse prognosis. Bladder cancer occurs after the fifth decade and more frequently in men than in women (sex ratio 3:1). The incidence of bladder cancer is highest in industrialized countries. It has been associated mainly with smoking, but also with occupational exposure to carcinogens from aniline dyes, paints, rubber, and chronic irritation of the bladder mucosa due to bladder stones, or schistosomiasis.