OBJECTIVE: The purpose of this pilot study was to compare the efficacy of 2 techniques for evaluating bladder function after transvaginal surgery. STUDY DESIGN: Subjects scheduled for transvaginal, outpatient surgery were consecutively enrolled and randomized to backfill-assisted voiding trial or a trial of spontaneous voiding after surgery. RESULTS: Sixty subjects were enrolled. The mean time in the perioperative anesthesia care unit for the backfill group was 199.5 minutes vs 226.6 minutes in the spontaneous voiding group (P = .08). Subjects randomized to backfill were more likely to adequately empty their bladders and be discharged home without catheter drainage than subjects in the spontaneous voiding group (61.5% vs 32.1%, respectively, P = .02). Multiple logistic regression further demonstrated that the backfill-assisted technique predicted successful bladder emptying after vaginal surgery (P = .02). CONCLUSION: Women undergoing transvaginal outpatient surgery are more likely to empty their bladder effectively before discharge if they are evaluated with a backfill-assisted voiding trial.