Objective Data: Robotic assistance may facilitate completion of minimally invasive hysterectomy, which is the standard of care for the treatment of early-stage endometrial cancer, in patients for whom conventional laparoscopy is challenging. The aim of this systematic review was to assess conversion to laparotomy and perioperative complications after laparoscopic and robotic hysterectomy in patients with endometrial cancer and obesity (body mass index, ≥30 kg/m2). Study: We systematically searched MEDLINE, EMBASE, and Evidence-Based Medicine Reviews (January 1, 2000, to July 18, 2018) for studies of patients with endometrial cancer and obesity (body mass index, ≥30 kg/m2) who underwent primary hysterectomy. Study Appraisal and Synthesis Methods: We determined the pooled proportions of conversion, organ/vessel injury, venous thromboembolism, and blood transfusion. We assessed risk of bias with the Institute of Health Economics Quality Appraisal Checklist for single-arm studies, and Newcastle-Ottawa Quality Scale for double-arm studies. Results: We identified 51 observational studies that reported on 10,800 patients with endometrial cancer and obesity (study-level body mass index, 31.0–56.3 kg/m2). The pooled proportions of conversion from laparoscopic and robotic hysterectomy were 6.5% (95% confidence interval, 4.3–9.9) and 5.5% (95% confidence interval, 3.3–9.1), respectively, among patients with a body mass index of ≥30 kg/m2, and 7.0% (95% confidence interval, 3.2–14.5) and 3.8% (95% confidence interval, 1.4–9.9) among patients with body mass index of ≥40 kg/m2. Inadequate exposure because of adhesions/visceral adiposity was the most common reason for conversion for both laparoscopic (32%) and robotic hysterectomy (61%); however, intolerance of the Trendelenburg position caused 31% of laparoscopic conversions and 6% of robotic hysterectomy conversions. The pooled proportions of organ/vessel injury (laparoscopic, 3.5% [95% confidence interval, 2.2–5.5]; robotic hysterectomy, 1.2% [95% confidence interval, 0.4–3.4]), venous thromboembolism (laparoscopic, 0.5% [95% confidence interval, 0.2–1.2]; robotic hysterectomy, 0.5% [95% confidence interval, 0.1–2.0]), and blood transfusion (laparoscopic, 2.8% [95% confidence interval, 1.5–5.1]; robotic hysterectomy, 2.1% [95% confidence interval, 1.6–3.8]) were low and not appreciably different between arms. Conclusion: Robotic and laparoscopic hysterectomy have similar rates perioperative complications in patients with endometrial cancer and obesity, but robotic hysterectomy may reduce conversions because of positional intolerance in patients with morbid obesity. Existing literature is limited by selection and confounding bias, and randomized trials are needed to inform practice standards in this population.