Background: Remimazolam is a novel ultrashort-acting benzodiazepine that has recently become available for general anesthesia. However, the incidence of postoperative nausea and vomiting (PONV) associated with remimazolam remains unknown. In this propensity score-matched, retrospective, observational study, we compared the rates of PONV between remimazolam and propofol. Methods: In this retrospective observational study, propensity score-matching was performed to minimize selection bias. Patients who received total intravenous anesthesia with remimazolam or propofol at the Hamamatsu University Hospital between August 2020 and July 2021 were enrolled in the study. Data on patient demographics, anesthetic agents, and PONV within the first 24 h were collected and analyzed. Results: Of the 1,239 patients who met the study selection criteria, 585 received remimazolam and 684 received propofol. After propensity score matching, 333 matched pairs were further analyzed. Patient demographics and the anesthetic agents used were comparable between the matched cohorts. The incidence of PONV was significantly higher in the remimazolam group than in the propofol group (35% vs. 21%, P < 0.001). Conclusions The incidence of PONV is higher with remimazolam anesthesia than with propofol anesthesia. The findings of this study require confirmation in larger prospective randomized controlled trials.