The prognosis of superficial bladder cancer in terms of recurrence and disease progression is related to the bladder tumor multiplicity and the presence of concomitant 'plane' tumors such as high grade dysplasia and carcinoma in situ (CIS). This study on 33 patients tries to demonstrate the interest of fluorescence cystoscopy in transurethral resection of superficial bladder cancer The method is based on the detection of the protoporphyrin IX (PpIX) induced fluorescence in urothelial cancer cells by topical administration of 5- aminolevulinic acid (ALA). The sensitivity and the specificity of this procedure on apparently normal mucosa in superficial bladder cancer is respectively estimated at 82.9% and 81.3%. Thus, fluorescence cystoscopy is a simple and reliable method in mapping the bladder mucosa, especially in case of multifocal bladder disease and it facilitates the screening of occult dysplasia. ©2005 Copyright SPIE - The International Society for Optical Engineering.