Urolithiasis is a rare urologic complication after kidney transplantation, and its diagnosis and treatment can be challenging for clinicians. In our 52-year-old male patient, graft hydronephrosis was found six months after transplantation. The patient had recurrent urinary tract infections followed by macrohematuria and an increase in creatinine levels. Computerized tomography revealed a 13-mm diameter stone in the ureter of the transplanted kidney as the cause of obstruction. Percutaneous nephrostomy was placed in the graft to solve the obstruction. Initial endoscopic treatment with a retrograde approach failed. An antegrade approach through a previously placed nephrostomy was not successful either. By a repeated retrograde approach, laser lithotripsy was performed successfully. The patient has been monitored for six months and has stable graft function without hydronephrosis or stones. As in our patient's case, the diagnosis and treatment of urolithiasis in kidney transplant patients is challenging, and minimally invasive procedures are the treatment of choice.Urolithiasis is a rare urologic complication after kidney transplantation, and its diagnosis and treatment can be challenging for clinicians. In our 52-year-old male patient, graft hydronephrosis was found six months after transplantation. The patient had recurrent urinary tract infections followed by macrohematuria and an increase in creatinine levels. Computerized tomography revealed a 13-mm diameter stone in the ureter of the transplanted kidney as the cause of obstruction. Percutaneous nephrostomy was placed in the graft to solve the obstruction. Initial endoscopic treatment with a retrograde approach failed. An antegrade approach through a previously placed nephrostomy was not successful either. By a repeated retrograde approach, laser lithotripsy was performed successfully. The patient has been monitored for six months and has stable graft function without hydronephrosis or stones. As in our patient's case, the diagnosis and treatment of urolithiasis in kidney transplant patients is challenging, and minimally invasive procedures are the treatment of choice.