A retrospective study of 161 patients with carcinomas of the bladder was carried out to assess the value of CT (247 examinations), transurethral sonography (32 examinations), and the early results of MRT. For TA-T3a staging, according to the TNM classification of the IUCC, transurethral sonography was particularly valuable. CT is useful for demonstrating transmural tumour growth (T3b) and organ invasion (T4), involvement of regional lymph nodes and distant metastases. Tumours in the roof of the bladder and at its base are well shown by MR tomography, using multiplanar sections.