PURPOSE To evaluate the safety and efficacy of the placement and exchange of tandem ureteral stents (TUS) under fluoroscopic guidance in the management of indwelling single double-J stent (DJS) failure in patients with malignant ureteral obstruction. We also aimed to investigate whether the generally accepted exchange period of DJSs could be extended using TUS. METHODS This retrospective study involved 11 patients (10 female) with an age range of 27–64 years, median of 49 years, who underwent TUS (ipsilateral two 8F DJSs) placement due to indwelling single DJS failure occurring in less than 3 months. TUS exchanges were performed initially at 6-month inter- vals, and subsequent exchange intervals were extended to 9 and 12 months for seven patients. The interval from initial TUS placement to percutaneous nephrostomy, repeat exchange, or death was defined as the duration of stent patency. RESULTS Indwelling single DJS failure occurred during a median follow-up of 45 days (range, 35–60 days) in 14 ureters of 11 patients. TUS were successfully placed and exchanged with a technical success rate of 100% without any early major complications. Thirty-nine procedures (11 placement and 28 exchange procedures) in 55 ureters were performed. The median duration of urinary patency was significantly higher with TUS [300 days (range, 60–440 days)] compared with single DJSs [45 days (range, 35–60 days)] (P < 0.001). CONCLUSION The placement and exchange of TUS can be safely and effectively performed under fluoroscopic guidance. The need for frequent DJS exchange could be reduced with increased duration of stent patency using TUS.