Background Malignant neoplasms of the bladder rank below common cancers such as breast, colon, cervix, liver, non-Hodgkin lymphoma and constitute less than 5% of all malignant tumours in most centres in Nigeria. Objectives This is the first time a comprehensive hospital study is being undertaken to determine the frequency of malignant bladder neoplasms in the Department of Pathology, Ahmadu Bello University Teaching Hospital, Zaria. The study covers the period of 20 years. Methods The study consisted of all diagnosed malignant urinary bladder neoplasms as recorded in the departmental registry of all specimens. Other information collated included all the relevant clinical bio-data as recorded. To authenticate the diagnoses, all slides of previously diagnosed cases were reviewed by me and supervised by the consultants. Where slides were broken, unclear or faded original tissue blocks from the archival stores where retrieved, sectioned and stained with routine 2 Haematoxylin and Eosin stains. The tumours were classified according to 2004 WHO classification of urinary bladder neoplasms