We report a rare case of duplication of the bladder, urethra, uterus, vagina, and associated anomalies in a woman. As an infant, she initially underwent successful surgical reconstruction. As an adult, she developed adenocarcinoma within the defunctionalized bladder moiety. The surgical management and pathology of this cancer are detailed and the pertinent literature reviewed. J. Surg. Oncol 1997;65:280–283. © 1997 Wiley‐Liss, Inc.