Radiologic investigation is a crucial source of clinical information for many disorders of the urinary bladder. Although ultrasonography is a common initial diagnostic modality for pediatric patients, both computed tomography (CT) and magnetic resonance imaging (MRI) are used to noninvasively evaluate the bladder. Urothelial carcinoma is overwhelmingly the most common bladder tumor, and MRI is a significant part of tumor staging and appropriate management planning. Recently, the Vesical Imaging-Reporting and Data System (VI-RADS) using multiparametric MRI has been widely used for urothelial cancer staging. Further, CT is helpful for assessing the lymph nodes and upper urinary tracts for synchronous or metachronous urothelial neoplasms in patients with bladder cancers. Nonurothelial neoplasms and mass-forming inflammatory disorders often mimic urothelial neoplasm, and clinical and pathologic correlation is indispensable. CT is the primary imaging technique used to evaluate patients with bladder trauma and patients who undergo cystectomy with a urinary diversion. Familiarity with the altered anatomy allows accurate interpretation of radiologic studies.