Urolithiasis is a rare complication after kidney transplant. Over the years, treatment of kidney stones has evolved radically, but a standard approach for transplanted kidneys has not yet been defined. Here, we present a 69-year-old male patient who received successful treatment of nephrolithiasis of the transplanted kidney. The patient, who had received a kidney from a deceased donor, was admitted to our department following a posttransplant Doppler ultrasonography showing severe hydronephrosis of the transplanted kidney associated with acute renal function decay. Computed tomography scan confirmed the hydronephrosis of the transplanted kidney, showing a large, impacted, ureteropelvic 3-cm-diameter stone and other concretions around the ureteral stent. The patient was then treated with retrograde intrarenal surgery during an open ureterotomy. His postoperative course was uneventful, and he showed good functional reprise and a rapid decrease of serum creatinine levels. Intraoperative retrograde intrarenal surgery could be a valid option for treatment of kidney stones of the transplanted kidney during open surgery of the ureter or during ureterovesical anastomosis.