To compare the hydrocoated silicone stent (Coloplast Imajin® hydro) to Percuflex Plus stent (Boston Scientific) in terms of patient comfort and quality of life after flexible ureteroscopy (fURS) for stone disease over a 5-week prospective follow-up.Materials and Methdos:This is a multicenter, single-blind, prospective, randomized trial of 141 patients treated with fURS for renal stones. Primary outcome was USSQ Body Pain Index recorded before DJ removal at day 20 (D20). Secondary endpoints were USSQ scores at intermediate dates (D2, D7, D20) and 2 weeks after stent withdrawal (D35), occurrence of adverse events and stent encrustation.The trial was completed by 113 (80.1%) patients. Mean (SD) USSQ body pain scores were 25% lower at D20 for the silicone stent: 18.7 (11.4) vs 25.1 (14.2), p=0.015. No difference in term of adverse events and safety profile was observed. USSQ urinary symptoms scores at D2, D7 and D20 were lower in the silicone stent group: 26.4 (7.7) vs 31.8 (8.1) at D20 p<0.001. The use of USSQ self-questionnaires was associated with a limited number of missing or incomplete answers.The primary results of this large sample prospective randomized controlled study comparing the silicone Imajin® hydro stents to the Percuflex Plus stent show that silicone stents are associated with significantly less patient discomfort. We would recommend their use in patients who require stenting for stone disease.Patient Summary:In this randomized prospective trial, silicone DJ stents Imajin® hydro result in lower pain and discomfort following flexible ureteroscopy as compared to Percuflex Plus.