Percutaneous removal of renal calculi is completed most often in the United States after initial placement of a retrograde ureteral catheter. Catheterization usually is accomplished with a rigid cystoscope with the patient in a dorsal lithotomy position, following which the patient must be turned to a prone position for percutaneous puncture and stone removal. We report our experience with the use of a flexible cystoscope with the patient in a prone position for placement of a retrograde catheter. In male patients this approach was difficult secondary to urethral length and angulation. Currently, in male patients we prefer a supine approach with the flexible cystoscope. In female patients the prone approach was performed easily. Among female patients prone cystoscopy for retrograde ureteral catheterization resulted in decreased operating room time, less manipulation of the anesthetized patient and creation of a 2-tiered field to maintain the sterility of the retrograde ureteral catheter. We found the prone approach to be feasible and effective in female patients.