Baboudjian M, Gondran-Tellier B, Abdallah R, et al. - Through a retrospective study that involved 604 consecutive flexible ureteroscopy (fURS) conducted from January 2015 to March 2019, experts examined the incidence and predictive risk factors of urinary tract infection (UTI) after fURS procedure. Nephrolithiasis management and diagnosis and conservative treatment of upper urinary tract urothelial carcinomas (UTUC) were the suggestions. For nephrolithiasis (n = 462) and UTUC management (n = 142), 604 fURS were involved in this study. In the study cohort, the median age was 61 years, a total of 268 female individuals were involved, the median Charlson score was 2 and single-use fURS were used in 186 cases. In 41 cases, postoperative UTI occurred. Hence, female sex, preoperative polymicrobial urine culture and raised operative time persisted to be correlated with postoperative UTI, in a large cohort study. Moreover, limiting operative time and enhancing the knowledge of polymicrobial urine cultures could decrease infectious risk.