To evaluate one-stage antegrade ureteral stent placement without postprocedural nephrostomy tube. Tubeless ureteral stent insertion was attempted in 41 (30 men, 11 women; eight, benign obstruction; nine outpatients) of 97 adults (56 excluded). Patients were clinically stable with known ureteral obstruction and had been referred for antegrade ureteral stent insertion. Exclusion criteria were infection, coagulopathy, or emergency cases. After renal access was achieved, ureteral stents were inserted. If drainage was satisfactory and there was no marked procedural bleeding, all access was removed without leaving a nephrostomy tube behind. Technical and clinical success rates and complications were assessed with review of radiologic and clinical notes. If one-stage stent insertion was unsuccessful, a nephrostomy tube was inserted and two-stage stent placement was performed. All 56 patients excluded from this study underwent two-stage stent placement. Major complication rate was assessed (Fisher test). One-stage stent insertion was technically successful in 36 (88%) patients; two with an identifiable risk factor (recent bladder operation, retrograde ureteral instrumentation) developed septicemia that required repeat nephrostomy tube insertion and 2-8 extra days of hospitalization. Clinical success rate was 83% (34 of 41). No major bleeding occurred. In 13 (36%) of 36 patients, hematuria lasted longer than 24 hours but resolved without further intervention or blood transfusion. In those who underwent two-stage stent placement (n = 61), technical success rate was 100%, but clinical success rate was 98%; one patient developed septicemia, and no major hemorrhage occurred. Difference in major complication rate between groups was not significant (6% [two of 36] vs 2% [one of 61]; P =.55). One-stage tubeless antegrade ureteral stent insertion in selected cases showed 88% technical success rate and 83% clinical success rate, with no major hemorrhage.