Although complications of sutures in transplantation are important, few studies have been designed to compare complications of absorbable and non absorbable suture. This study was performed to determine association between hydronephrosis and fine prolene (non absorbable suture) or Catgut chromic (absorbable suture) in ureteral anastomosis in kidney transplantation. This study is an experimental interventional survey. 115 patients whom their ureteral anastomosis was performed with Catgut chromic and 105 patients with fine prolene were included in our study. The ureteral implantation was performed with modified lich technique. All patients were followed for 18 months. Hydronephrosis was diagnosed with sonography, VCUG and IVP were performed if hydronephrosis was detected. The analyses were done with SPSS. P value <0.05 was considered significant. At least 4 patients (3.5%) in catgut chromic group had hydronephrosis that three patients had urinary collection and one patient had ureteral stricture. 10 patients (9.5%) in catgut chromic group had hydronephrosis that two patients had urinary collection, one patient had subcutaneous hematoma and one had urinary stone. In our study collections in prolene group was not more than catgut chromic group and prolene can be used in ureteral implantation in renal transplantation.