Objective: Flexible cystoscopy for ureteral stent removal after ureteroscopy is widely performed. In this scenario, the real need for antimicrobial prophylaxis is still uncertain. Aim of this study is to determine the urinary tract infections rate after 4 weeks from outpatient flexible cystoscopies for ureteral stent removal without antimicrobial prophylaxis. Patients and methods: A prospective observational study was performed between November 2017 and August 2018 in a single, high-volume Institution. Risk factors for UTIs were recorded. Immediately before cystoscopy, each patient submitted a voided urine specimen. Antibiotics were not given before or after cystoscopy. About 7 and 28 days after cystoscopy all the patients underwent abdomen US, urine analysis and culture, and clinical evaluation to assess possible symptoms of UTI. Results: A total of 192 patients were enrolled in the study, 76 patients (39.2%) were female. Median age was 55 years [IQR 47- 68]. Median BMI was 24.2 [22.9-26.7]. Eighteen patients (9.4%) had asymptomatic bacteriuria before cystoscopy and 39 (20.3%) had positive culture at 7 days. About 21 patients (10.9%) were diagnosed with febrile UTI in the 28 days FU period. The 28.6 % of the Febrile patients had asymptomatic bacteriuria before the stent removal ( p < 0.001), this group was slightly older ( p = 0.085) and with higher BMI ( p = 0.036). Forty-eight patients had positive urine culture at 7 days, of whom 27 (14.1%) were asymptomatic and were classified as asymptomatic bacteriuria. Multivariate analysis shows that only high BMI and bacteriuria before the procedure were significantly associated with developing a febrile UTI, none of the other risk factors was significant. Conclusion: Our data show a high rate of UTI after flexible cystoscopies for ureteral stent removal without antimicrobial prophylaxis especially in patients with asymptomatic bacteriuria, in those with high BMI and in the elderly; in these subgroups, antimicrobial prophylaxis should be recommended.