Abstract: OBJECTIVE To investigate the current status, etiological characteristics and influencing factors of urinary tract infection in patients after flexible ureteroscopic lithotripsy. METHODS The clinical data of 304 patients after flexible ureteroscopic lithotripsy in Danzhou People's Hospital from Jan 2020 to Dec 2022 were retrospectively analyzed. According to whether postoperative urinary tract infection occurred, the patients were divided into the infection group (35 cases) and the non-infection group (269 cases). The status of urinary tract infection and the distribution of pathogenic bacteria in patients after flexible ureteroscopic lithotripsy were recorded. The risk factors for urinary tract infection in patients after flexible ureteroscopic lithotripsy were analyzed by univariate and multivariate analysis. RESULTS There were 35 cases of urinary tract infection in 304 patients after flexible ureteroscopic lithotripsy, and the incidence of urinary tract infection was 11.51%. A total of 39 strains of pathogenic bacteria were detected in 35 patients with urinary tract infection after flexible ureteroscopic lithotripsy, mainly gram-negative bacteria. Multivariate logistic analysis showed that preoperative urinary tract infection, diabetes mellitus, and double J catheter indwelling time >14 days were the risk factors for urinary tract infection in patients after flexible ureteroscopic lithotripsy (P＜0.05). CONCLUSION The incidence of urinary tract infection in patients after flexible ureteroscopic lithotripsy is high, and the pathogenic bacteria is mainly gram-negative bacteria. Preoperative urinary tract infection, diabetes mellitus, and double J catheter indwelling time >14 days are closely related to the occurrence of urinary tract infection in patients after flexible ureteroscopic lithotripsy. So, early targeted prevention and treatment can be carried out to reduce the risk of urinary tract infection in patients after flexible ureteroscopic lithotripsy.