Nowadays in most of renal transplantation (RTX) centers to prevent the urinary leakage and to facilitate healing of the anastomtic site of donor kidney ureter to recipient bladder, the DJ catheter is used as a ureteral stent. In this article we have evaluated the problems which are due to usage of ureteral stent after RTX. Since March 1989 until March 2007, 1300 RT were performed in our center by a fixed surgical team. Politano – ledbetter was the technique of ureteral anastomosis in the first 55 cases. The remainder of patients the U.V anastomosis was done by extravesical technique and we used Dj – Stent for these ureters. In 35% of female and 32% of male patients we used a short Dj stent (16 cm) and fixed it with a chromic suture to bladder mucosa. For others patients we didn't shorten the Dj – stent or fix it to bladder mucosa. Duration of remaining Dj – stent in the anastomosis ureter varied from 5 to 6 weeks. In 16 patients upward migration of Dj – stent occurred that in 15 cases and we removed the stent by ureteroscope and in one patient we used percutaneous nephrostomy for removing stent. In 85 recipient patients we encountered downward migration and entrance of ureteral DJ stent to the urethra. Upward or downward migration of the stent occurred in recipient's whose stent was not fixed (P<0.01) or the length of stent was longer than 16 cm (P < 0.01). Encrustation occurred around Dj – stent in 45 patients and this didn't allow stent to be drawn out, therefore we drew out the stent by endoscopic procedures in 11 patients. In conclusion, displacement of the ureteral DJ stent especially upward migration and encrustation around the stent are two serious complications after RTX. To prevent migration we advise to select a short length stent and to fix it to the bladder mucosa. Finding the causes of encrustation and ways to prevent it needs further investigation.