Two cases of primary adenovillous carcinoma of the bladder are presented: one in a normally placed bladder and the other in an exstrophied bladder. The close association of these 2 neoplasms with coexistent cystitis glandularis would seem to support the possible precancerous nature of the latter entity. The remarkable similarity of these neoplasms to villous adenocarcinomas of the rectum is also described, a finding which may reflect the close embryologic origin of the rectum and bladder neck. A brief review of the classification of vesical adenocarcinomas is also given.