70% of our patients suffering from bladder cancer present themselves initially with a superficial tumor (Tis, Ta, T1) and only 30% are initially seen with a muscle-invasive carcinoma (T2, T3–4, N+, M+). Clinical history, physical examination, urine cytology, IVP and cystoscopy in combination with adequate tissue harvest by transurethral resection are the basis of our diagnostic procedures. Bimanual palpation, systematic biopsies, sonography, computed tomography, bone scan and further procedures are not to be considered as routine examinations and are only used in special situations. Only exactly defined diagnostic algorithms permit the development and use of valid prognostic parameters. They further allow to perform a tumor-orientated therapy and to compare patient groups which have been treated in different institutions according to similar or different therapeutic regimens. This includes the importance of a TNM-oriented therapy. It has to be stressed though that the prevalence of distinct pathological changes, such as bone metastases in T1 tumors, as well as financial resources, have to be taken into account. Further, definite therapeutic intention such as a curative vs. palliative regimen is a decisive criterium for the amount of performed diagnostic procedures. It also is of importance that new diagnostic modalities, if introduced into the clinical routine, have to be investigated concerning their validity in relevant and large patient cohorts and their rationale in our diagnostic algorithm has to be defined. This is predominantly not the case in radiological imaging techniques and thus a large amount of resources are wasted.