The definitive diagnosis of bladder cancer is established at cystoscopic examination and confirmed by means of a transurethral biopsy. A careful bimanual palpation of the bladder under anesthesia is an integral part of the initial assessment of each patient. The most important part of the assessment of patients with bladder cancer is a thorough pathologic examination of the biopsy material establishing the histologic type of tumor, histologic grade, tumor configuration, depth of invasion of the bladder wall, and depth of the bladder wall available for assessment. If possible, the size of the tumor and the presence of associated carcinoma in situ should also be reported. Imaging studies play a smaller role in the clinical staging of bladder cancer. However, when initial staging procedures point to invasion of the muscularis propria, chest X-ray, bone scan, and computed tomography scan of the abdomen and pelvis may provide valuable information about possible metastases. Whereas the clinical staging is essential to select and evaluate therapy, the pathologic stage (pTNM) provides the most precise data with which to estimate prognosis and calculate end results. The pathologic assessment entails resection of the primary tumor or a biopsy adequate to evaluate the highest pT category, removal of lymph nodes adequate to validate the absence of regional lymph node metastasis, as well as biopsy and microscopic examination for assessment of distant metastases. Although numerous factors have an impact on the behaviour of the malignancy, in bladder cancer the anatomic extent of disease reflected in the current staging classification remains the most powerful indicator of outcome.