Abstract: From June 1977 to September 1980. 180 cases of bladder tumors were treated by injecting aluminum sulfate co. into the base of the tumor through cystoscope wth en-couraging results. Two weeks after the initial injection. follow-up cystoscopy was carried out to see whether tumor was completely destroyed. If fhe tumor was not completely destroyed. an additional injection was made to destroy the residual tumor. This treat-ment is effective in non-infiltrating or superficially infiltrating pedunculated papillary tumors. The largest tumor was measured 6 cm. in diameter. 164 of 180 cases thus treated were considered to be cured. The remaining 16 cases required further treatment. because complete destruction was not achieved. No remarkable side-effects were observed during the course of treatment. except for slight local pain. No recurrence was found at the site of the primary tumors.