<p>To explore the independent risk factors for urosepsis in patients with symptomatic ureterolithiasis undergoing ureteroscopic lithotripsy (URSL) and to construct a clinically applicable predictive model for the early identification of high-risk patients to reduce the possibility of postoperative urosepsis.This study included 944 patients with symptomatic ureterolithiasis treated with URSL, and these patients were randomly divided into a training set and a validation set at a 7:3 ratio. Independent risk factors were screened by univariate and multivariate logistic regression analyses, and predictive models were constructed based on these variables. The area under the receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA) were used to evaluate the discrimination, calibration, and clinical applicability of the nomogram. A total of 89 patients in this study developed urosepsis after URSL. Multivariate logistic regression analysis showed that positive urinary nitrite (OR = 3.418, 95%CI: 1.470-7.982), operative time (OR = 1.022, 95%CI: 1.012-1.033), positive urine culture (OR = 3.549, 95%CI: 1.793-6.961), hemoglobin (OR = 0.979, 95%CI: 0.964-0.994), and perirenal fat stranding (OR = 4.523, 95%CI: 1.891-10.801) were independent risk factors for urosepsis after URSL in patients with symptomatic ureterolithiasis. The areas under the ROC curve for this nomogram in the training set and the validation set were 0.872 (95%CI: 0.830-0.915) and 0.872 (95%CI: 0.806-0.939), respectively, indicating good prediction ability. The calibration curve showed good consistency, and DCA demonstrated that the model had a high clinical net benefit. The predictive model, including positive urinary nitrite, operative time, positive urine culture, hemoglobin, and perirenal fat stranding, was constructed, which can effectively estimate the risk of urosepsis in patients with symptomatic ureterolithiasis after URSL.</p>