Objective: To assess the diagnostic accuracy of a retrograde voiding trial for predicting spontaneous voiding function. Methods: This retrospective cohort study included patients who underwent operations for correction of pelvic organ prolapse, urinary incontinence, or both, between April 2019 and January 2022 in a tertiary hospital. Sequential voiding trials were performed in all patients on postoperative day 1-3; a retrograde voiding trial was performed first, followed by a spontaneous voiding trial. During both trials, voided volume (VV) was recorded and postvoid residual (PVR) was measured by catheterization. Restoration of spontaneous voiding function was defined as PVR ≤ 150 mL with a void of ≥ 150 mL for two consecutive spontaneous voids. Area under the curve (AUC) was calculated as a measure of predictive performance, and optimal cut-off values of voiding efficiency (VE, VV/[VV+PVR]) and PVR for retrograde voiding trials were determined by the Youden index. Results: Of 408 women analyzed, 278 (68.1%) passed the spontaneous voiding trial on the day of voiding trial without returning to clinic with symptoms of urinary retention post-discharge. ROC analyses showed that VV, PVR and VE of retrograde voiding trials all accurately predicted spontaneous voiding function, while PVR and VE showed even better performance than VV (AUC of 0.93 for PVR, 0.94 for VE and 0.88 for VV, DeLongs test between PVR/VE and VV p< 0.01). The optimal cutoffs for predicting spontaneous voiding function were > 66.7% for VE and ≤ 120 mL for PVR. Conclusion: We found that the retrograde voiding trial is an accurate predictor of restoration of spontaneous voiding function after prolapse and incontinence surgery, and measuring PVR during the voiding trial will further increase its diagnostic accuracy.