Background/Objectives <p>Ureteral obstruction is an uncommon but clinically significant complication following benign hysterectomy and may remain asymptomatic until renal impairment develops. Current guidelines do not recommend routine postoperative ultrasonography; however, earlier detection of obstruction may facilitate timely intervention and preservation of renal function. This study aimed to evaluate the diagnostic performance of a structured, two-step postoperative renal ultrasonography protocol.</p> Methods <p>This single-center diagnostic accuracy study retrospectively analyzed 725 patients who underwent benign hysterectomy between January 2023 and June 2025. Renal ultrasonography was performed by the same radiology team using a standardized protocol. Hydronephrosis graded ≥ 2 according to the Society for Fetal Urology classification was considered positive. Computed tomography or urologic evaluation served as the reference standard. Sensitivity, specificity, predictive values, accuracy, and Youden indices were calculated.</p> Results <p>Seven patients (0.9%) were diagnosed with ureteral obstruction. On postoperative day 3, ultrasonography demonstrated a sensitivity of 85.7%, specificity of 99.3%, and a negative predictive value of 99.9%. Of 11 positive findings, six were confirmed as true obstructions, while five represented transient pelvic dilatation. On postoperative day 10, specificity increased to 99.5% and sensitivity reached 100%, reflecting resolution of early false-positive findings. Six obstructions were detected on day 3, and one newly developed obstruction was identified on day 10. All affected patients underwent appropriate intervention, and no short-term loss of renal function was observed in the confirmed cases.</p> Conclusions <p>A two-step renal ultrasonography protocol performed on postoperative days 3 and 10 demonstrated very high specificity and negative predictive value in a very low-prevalence setting for ruling out early postoperative ureteral obstruction after benign hysterectomy. These findings are preliminary and hypothesis-generating due to the low number of outcome events and should be validated in prospective, multicenter studies, including evaluation of feasibility, cost-effectiveness, and patient-reported outcomes, as well as the performance of gynecologist-performed point-of-care ultrasonography (POCUS).</p> Trial registration <p>Not applicable. This study did not involve prospective assignment of a healthcare intervention.</p>