Two hundred eight patients with upper urinary tract stones were treated by retrograde intrarenal surgery (RIRS) using a flexible deflectable ureteroscope after 1 to 2 weeks of ureteral dilatation with an indwelling double-J stent. Eventually, 87% of the patients were made stone free. The RIRS proved particularly helpful in cases with associated intrarenal stenosis, nephrocalcinosis, supravesical urinary diversion, or bleeding disorders and in patients with a need for complete stone removal. No complications were directly attributable to the RIRS technique. Although RIRS is technically demanding and can be time consuming, it has evolved into a standard procedure for a number of stone indications at the author's institution.