Febrile urinary tract infection (f-UTI) is a common complication after ureterorenoscopic lithotripsy (URSL) but is sometimes lethal. In this article, we analyzed the factors of post URSL f-UTI. We retrospectively evaluated the association between the development of f-UTI and patients, stones, and perioperative factors in 695 cases in which URSL was performed at our institution from September 2015 to 2018. Seventy-six of the 695 patients (10.9%) had postoperative f-UTI. Elderly (p＝0.013), female (p＝0.02), and hypertension (p＝0.001) patients had significantly higher rates of f-UTI. Renal stone (p＝0.001) cases showed significantly higher rates of f-UTI. Preoperative urine positive culture (p＝0.045), preoperative f-UTI (p＜0.001), URSL procedure using flexible ureteroscopy (p＝0.048), non-stone-free (p＝0.006), long operation time (p＝0.011), preoperative urinary stent insertion due to preoperative f-UTI (p＜0.001), were factors associated with post-operative f-UTI. Multivariate analysis revealed that hypertension (OR＝2.08, p＝0.008) and preoperative f-UTI (OR＝3.739, p＝0.033) were independent factors of postoperative f-UTI. Patients with hypertension or preoperative f-UTI should be managed more carefully during the perioperative period, suspecting that they are more likely to develop postoperative f-UTI.