Objective: To evaluate the effect of head-down tilt on airway pressure in gynecologic patients with obesity during robot-assisted hysterectomy. Methods: We retrospectively reviewed the records of 27 patients with body mass index (BMI) ≥ 25 kg/m2 who underwent robot-assisted hysterectomy for endometrial cancer and endometrial atypical hyperplasia using the da Vinci Xi system. Mechanical ventilation was performed using pressure-controlled ventilation (PCV). Surgery was performed at 20° (group A, n = 17) or 25° head-down tilt (group B, n = 10). Respiratory parameters, including positive end-expiratory pressure (PEEP), tidal volume (TV), mean airway pressure (P mean), and peak airway pressure (P peak), were measured before (T1) and after the head-down tilt at 1 h (T2) and 2 h (T3) during anesthesia. Results: The median BMI was 37.5 (range 28-51) kg/m2, with no between-group variation. Oxygenation was maintained intraoperatively for all patients. The expiratory carbon dioxide partial pressure was 43.6 (95% confidence interval (CI) 42.2-45.0) mmHg. The P mean peak at T2 in group B was significantly higher than in group A (P < 0.011); however, other parameters at T2 and T3 did not differ significantly between the groups. Patients with BMI ≥ 40 kg/m2 had significantly higher respiratory parameters than those with BMI < 40 kg/m2. In patients with BMI ≥ 40 kg/m2, the mean P means and P peaks at T3 were 17.3 cmH2O (95% CI 16.3-18.3) and 29.4 cmH2O (95% CI 27.1-31.7), respectively. Discussion: With careful anesthetic management during PCV, robot-assisted surgery with a head-down tilt of 25° or below may be safe, even in patients with class III obesity.