Abstract : To compare the outcomes of management of ureteropelvic junction obstruction by open pyeloplasty using a stent or without a stent. Operating on a total of 48 patients diagnosed with UPJO randomly allocated to either group (I): patients managed with double J stent including 24 patients or group (II): the non-stented group (24 cases). Dismembered pyeloplasty was performed for the two groups. The obtained results showed that, after 1 week of the surgical procedure, group (II) had a significantly higher rate of complications as compared to group (I). However, urine analyses didn’t differ significantly among both groups. At six weeks post-operative, dysuria was the significant complaint among the group (I) compared to group (II). The percentage of patients with no complaint was higher among the group (II) compared to group (I). Post-operative hydronephrosis after six weeks was higher in the group (II) compared to group (I). GFR and split function were significantly higher among group A patients after three months postoperative in comparison to group B patients. Significant improvement was noted in patients managed with DJ stent compared with those non-stented regarding postoperative hydronephrosis, GFR, and split function when assessed by postoperative ultrasound (U/S) and DTPA, giving the high priority for the stent use in patients with UPJO.