Study Objective: To identify risk factors associated with postoperative urinary retention in patients undergoing outpatient minimally invasive hysterectomy. Design: A retrospective cohort study. Setting: An academic medical center. Patients: All patients undergoing outpatient minimally invasive hysterectomy between January 2013 and July 2018 were considered for inclusion in the study. Interventions: Outpatient laparoscopic, vaginal, or robotically assisted laparoscopic hysterectomy. Measurements and Main Results: Four hundred forty-four patients met the inclusion criteria. Postoperative urinary retention occurred in 94 patients, and 347 patients successfully passed their voiding trial in the postanesthesia care unit for a pass rate of 79%. Demographic characteristics were similar, except patients who experienced postoperative urinary retention were less likely to be menopausal (23.4% vs 34.7%, p =.038). Those with urinary retention received more perioperative opioids (morphine milligram equivalent of 14.4 mg vs11.2 mg, p =.012), had longer operative times (122.9 +/- 55.6 vs 95.7 +/- 42.3 minutes, p <.01), and experienced more blood loss (105.3 +/- 134.4 vs 78.5 +/- 86.8 mL, p =.025). The rate of urinary tract infections was similar. Logistic regression analysis showed that the route of hysterectomy and age were not associated with an increased risk for urinary retention, whereas a longer operative time and higher doses of perioperative opioid use were. Conclusion: In patients undergoing minimally invasive outpatient hysterectomy, a longer operative time and increased perioperative narcotic use increases the risk of postoperative urinary retention. (C) 2019 AAGL. All rights reserved.