To choose the best attitude in front of the obstruction of the higher urinary tract secondary at a pelvic or retroperitoneal tumor is delicate and very often requires a multidisciplinary approach. The mains indications on the invasive minimal urinary derivations are the prolongation of life expectancy by the safeguarding of the renal function and the improvement of the quality of life during the presence of pains. The opinion of the patient is central to make decision. The two techniques of drainage which are the ureteral stent and the percutaneous nephrostomy have proved their efficiency.