Primary signet ring cell adenocarcinoma of the bladder accounts for less than 1 per centof all primary bladder neoplasm. 19 cases have been reported in the literature. This tumor is insidious because of its subepithelial infiltrative nature, which makes diagnosis possible only late in the course of the disease. Survival is poor ; greater 50 per cent of the patients are dead within a year after diagnosis.Radical surgery offers the only hope of palliation ; irradiation and chemotherapy have notbeen effective. We are reporting two cases of primary signet ring cell adenocarcinoma of the bladder treatedwith radical cystectomy with pathological findings and review of the literature.