Self-retaining silicone ureteral stents are used for prolonged urinary drainage in situ. Thanks to the exceptional patient tolerance, they appear to be the best indwelling catheters for the treatment of ureteral obstruction due to cancer. Eighteen catheters were placed in sixteen patients. Endoscopic insertion was carried out in 8 patients (9 catheters were inserted; one patient requiring bilateral catheterisation). An operative procedure was necessary in the remaining 8 cases: in 4 cases a simple ureteral dissection was necessary, whereas ureterostomy had to be carried out in the 5 remaining cases. During the treatment, the patient tolerance was excellent. Mean survival time, after catheterisation was 5,5 months and one patient had a functional catheter for 15 months. Obstruction of the catheter was observed in 3 cases but ureterostomy was avoided in 7 cases and 8 kidneys were protected in 6 cases. The palliative use of the double J catheter when no other treatment is possible for malignant ureteral obstruction precludes the need for ureterostomy. These catheters can be used for strategic curative treatment if nephrotoxic drugs are required to treat obstructive tumors of the ureters. Bladder disease is a contra-indication to the use of these catheters although their insertion is rarely impossible. In cases of acute obstruction, it is better to prepare the pathway with a traditional catheter, which is easier to manage, it is always possible to insert a double J catheter after some time has elapsed.