Objectives Exposure to chemical weapons and depleted uranium (DU) during multiple wars has a tremendous impact on public health in Iraq. This study conducted to evaluate the regional differences in the effects of these weapons on the histological features of bladder cancer (BC), a cancer form highly associated with environmental risk factors. Patients and MethodsFrom 172 BC patients enrolled in the study 123 were living in the Kurdistan Region (KR) of Iraq and 49 were living in the Rest of Iraq (RI). Medical history, clinical examinations, biochemical investigation and Transurethral Resection of Bladder Tumour (TURBT) or Radical Cystectomy (RC) were performed. Specimens were collected for histopathological examination. SPSS program (V18) used for statistical analysis. Results and DiscussionThe results showed that there are significant differences between the KR and the RI patients in terms of tumour grading and cellular features. Patient samples from the KR patients exhibit high percentage of well differentiated tumours, conversely RI exhibit high percentage of poorly differentiated tumours. Furthermore, histopathological examination showed that majority of tissue samples from KR were transitional cell carcinoma (TCC). The same was true for RI, though previously a higher proportion of tissue samples were squamous cell carcinoma (SCC) in RI. ConclusionThe tumour grading and histopathology showed more advanced cancers in patients living in RI compared to those living in KR. This is because weapons exposure is correlated with cancer aggressiveness of the tumour. Sex differences were obvious as in Iraq only males were participating in military service.