Flexible ureteroscopy combined with Holmium-YAG laser is an effective, reproducible and minimally traumatic diagnostic and therapeutic technique perfectly adapted to diseases of the upper urinary tract. This technology must be part of the therapeutic armamentarium of any centre involved in the management of urinary stones. The technical facilities must be complete and adapted. Flexible ureteroscopy is a technique with a rapid learning curve once the operator is familiar with all of the equipment. This article describes the material and technique of flexible ureteroscopy combined with Holmium-YAG laser.