Introduction: The aim of our study was to retrospectively evaluate the stone-free rate after the second intervention for every performed procedure (semirigid ureteroscopy, flexible ureteroscopy, semirigid plus flexible ureteroscopy and percutaneous nephrolithotomy). Materials and methods: A total of 149 patients, who came to the emergency room of "Saint John" Emergency Clinical Hospital, Bucharest, Romania, with acute renal pathology suggesting the presence of renal and/or ureteral lithiasis confirmed by imagining (x-ray, ultrasonography or computer tomography), were included in this retrospective study, which was conducted between September 2021 and September 2022. All selected patients had an indication of emergency surgical intervention that consisted of a double-J stent mounting. We analyzed the stone-free rate after the secondary intervention, which was one of the following procedures: semirigid ureteroscopy, flexible ureteroscopy, combined semirigid and flexible ureteroscopy (F-URS), and percutaneous nephrolithotomy (PCNL). Patients came back for the secondary intervention and were reevaluated using imaging techniques. Results:Endoscopic procedures were performed by 14 surgeons over a time period of two to six weeks after the initial stenting procedure. Encrusted stents were encountered in four cases and in five cases the patients were admitted with obstruction of previously inserted stents. From the total of 149 patients, 68 (45,6%) subjects underwent semirigid ureteroscopy, with a stone-free rate of 86% (59 cases), 32 (21,4%) F-URS, with a stone-free rate of 90,6% (30 cases), 41 (27,5%) combined flexible and semirigid ureteroscopy, with a stone-free rate of 90,24% (37 cases), and eight (5,3%) patients received PCNL, with a stone-free rate of 75% (six cases). Overall stone-free rate for all procedures was 90,06%. The mean operative time was 23 minutes. No major incidents or complications occurred during the procedures. Conclusion:The emergency pre-stenting before the definitive treatment of reno-ureteral lithiasis is a safe procedure. Flexible ureteroscopy was the most successful secondary intervention, with the highest rate of achieving stone-free status.