Background/Aim.Ureteroscopic lithotripsy is today a safe method of endoscopic destruction of stone in the kidney and ureter with a small number of complications of which the most common is postoperative urinary tract infection. Risk factors for the occurrence of urinary tract infection after the ureteroscopic destruction of stones in the ureter and kidney in the previous studies are not clearly defined. Methods. The study included 389 patients with ureteroscopic lithotripsy and possible risk factors were analyzed: age of the patient, sex, diabetes, presence, and degree of hydronephrosis, stone size, stone localization, wear of ureteral JJ stent and percutaneous nephrostomy catheter, type of surgical procedure and the duration of the operation. The frequency of postoperative urinary tract infection was statistically analyzed in relation to the possible risk factors. Results. 10% of patients had postoperative urinary tract infection. The higher incidence of postoperative urinary tract infection was found in patients with diabetes (X 2 =22.918; p<0.001), who before surgery carried a ureteral JJ stent (X 2 =4.620; p=0.040) and percutaneous nephrostomy catheter (X 2 =8.240; p=0.004), which had a larger stone (Z=-3.301; p=0.001), and in patients whose surgery lasted longer (t=4.261; p<0.001). Discussion. The risk of postoperative urinary tract infection following ureteroscopic lithotripsy is not negligible and is not clearly defined in the existing literature. Many authors examined risk factors for the emergence of postoperative urinary tract infections after ureteroscopic lithotripsy with different results and frequency. The frequency of postoperative urinary infection and risk factors for its emergence in our study are in line with the results of studies by other authors. Conclusion. Patients with diabetes, who preoperatively carried JJ stent or a percutaneous nephrostomy catheter, who had large stones and in which the operating time is longer have a greater risk of developing postoperative urinary tract infection. Accordingly, the importance of identifying these patients in the preparation for ureteroscopic lithotripsy contributes to the appropriate preoperative preparation and decreases the frequency of postoperative urinary tract infection to a minimum.