PURPOSE: We examined the sensitivity and specificity of Hexvix (PhotoCure ASA, Oslo, Norway) hexyl aminolevulinate (HAL) fluorescence cystoscopy in patients with superficial bladder cancer. MATERIALS AND METHODS: A total of 52 patients (38 men and 14 women) with a mean age of 72 years were investigated. HAL hydrochloride (100 mg dissolved in 50 ml phosphate buffer solution) (8 mM) was instilled into the bladder 1 hour prior to the endoscopic procedure. Cystoscopy was performed with the Storz D-light (Karl Storz, Tuttlingen, Germany) system, allowing inspection of the bladder wall under white and blue light (380 to 450 nm). RESULTS: A total of 422 biopsies obtained in fluorescing (165) and nonfluorescing (257) areas, including 5 random biopsies per patient, were analyzed to provide the best reference for the calculation of sensitivity and specificity. There were a total of 143 histologically verified tumors in 45 patients, including carcinoma in situ (CIS), Ta or T1 lesions. A total of 43 patients were diagnosed by fluorescence cystoscopy compared with 33 diagnosed by white light for 96% and 73% per-patient sensitivity, respectively. HAL cystoscopy was found particularly useful for finding CIS tumors. Of 13 patients with CIS tumors all except 1 were diagnosed or confirmed by HAL cystoscopy. HAL cystoscopy was well tolerated with no definite drug related adverse events reported, including effects on standard blood parameters. CONCLUSIONS: HAL fluorescence cystoscopy is a new, sensitive, promising diagnostic procedure that showed improved detection of bladder tumors, in particular CIS. The procedure is well tolerated and can easily be implemented in current clinical practice.