Intravesical chemotherapy can be employed either in a therapeutic aim or as an adjuvant prophylactic treatment after TUR. In this paper a discussion is presented about various controversial points that need to be clarified with regard to topical chemotherapy, with special reference to the selection of the drug and to various modalities of treatment. Some results are presented from the literature and from the author’s personal experience, with emphasis on the randomized clinical trials performed by EORTC and by other workers or groups.