One invasive and 4 superficial bladder cancers were treated by local injection of absolute ethanol through an endoscope. With the patient placed in the lithotomy position, an endoscope was introduced after mucosal anesthesia with xylocaine jelly. According to the usual manner of retrograde catheterization, a 23G syringe needle attached to a 5F ureteral catheter was advanced into the base of the tumor and through the needle absolute ethanol was injected. This treatment is characterized by endoscopic delivery of ethanol as with sclerotherapy for esophageal varices to obtain a potent necrotizing effect as achieved by transcatheter embolization of ethanol for the treatment of renal cell carcinoma. As a rule, this technique does not require any anesthesia other than mucosal anesthesia with xylocaine jelly and can be done repeatedly and very easily, thus having a high cost effectiveness. This treatment serves as a good palliative therapy for invasive bladder cancers, because of its rapid achievement of hemostasis and reduction of the tumor masses. Furthermore, this treatment is just as effective as standard transurethral resections to eradicate superficial bladder cancer, even though the treatment may have to be repeated.