The use of percutaneous nephrostomy with or without placement of a ureteric stent has been of increasing aid in treating both acute and chronic ureteral obstruction in recipients of renal allografts. Eight patients who underwent transplantation, had ureteric obstruction develop and were treated by this means are reported herein. The technique is standard and can be performed in an arteriography suite. Once a catheter is inserted into the allograft collecting system, a nephrostomy tube or a stent, or both, is easily inserted. Three of the patients had acute ureteric obstruction secondary to clot forming after needle biopsy of the transplant kidney. Percutaneous nephrostomy tubes were passed, the renal pelvis and ureter irrigated and the clots lysed. Operation was unnecessary. In five patients with declining renal function secondary to chronic obstruction, percutaneous nephrostomy placement allowed return of renal function to base line levels, while placement of a stent through the ureter into the bladder facilitated location of the ureter at operation for ureteral reimplantation. The technique of percutaneous nephrostomy is simple, convenient and allows patient recovery preoperatively. It has become part of our standard armamentarium in transplant recipients.