There is currently a renewed interest in laser in the field of urology, essentially for the treatment of benign prostatic hypertrophy, as a result of recent developments in the field of fibres. Laser is light coherent in time and space emitted continuously or in pulses. Only its thermal and photochemical properties are used in urology. Endoscopic coagulation of superficial bladder tumours by Nd YAG laser does not seem to be better than classical endoscopic resection, at the present time, as although it is less haemorrhagic, it does not decrease the recurrence rate. Photochemotherapy of bladder carcinoma in situ still constitutes a complex treatment protocol reserved for specialized centres. Lastly, upper urinary tract tumours can be treated by Nd YAG laser coagulation, in rare indications which are the same as those of ureteroscopic or percutaneous resection. The recent development of lateral firing laser fibres and contact tip fibres has led to a renewed interest in laser in benign prostatic hypertrophy. Two different techniques have been proposed: Nd YAG laser coagulation under direct visual or ultrasound control (TULIP), which gives delayed objective results (two or three months) and contact tissue vaporization (Nd YAG, diode), whose effects are more immediate. In both cases, intraoperative bleeding is minimal and the length of hospital stay is decreased, but the duration of urine drainage remains to be defined. Endoscopic pulsed laser urinary lithotripsy (dye, Ho YAG), although effective and atraumatic, is not justified at the present time because of its high cost compared to mechanical percussion lithotripters. Lastly, laser treatment for urethral stricture has not been found to be superior to classical scalpel urethrotomy and laser tissue welding is still in the experimental stages. In conclusion, laser technology, especially fibers, has currently reached an important phase of development with applications for urological disease, essentially in the treatment of benign prostatic hypertrophy in order to reduce the morbidity of classical endoscopic resection. However, other urological applications of laser could be validated in the near future due to the development of less expensive lasers (diode) and/or with multiple functions (Ho YAG).