Background:Adoption of laparoscopic surgery for cancers requiring partial or total proctectomy has been slow due to difficulty of achieving oncologically adequate resection. Obesity is a factor complicating use and outcomes of laparoscopic technique for rectal surgery. Impact of obesity on the outcomes of robotic rectal surgery for cancer is not well defined. This study is designed to assess whether if the robotic technique has potential to overcome the limitations of obesity and to improve outcomes of minimally invasive rectal surgery for cancer.Patients and Methods:Patients undergoing robotic sphincter-saving radical resection with da Vinci Xi System between December 2014 and December 2016 were included. Patients were divided into 2 groups as obese and nonobese. Patient demographics, perioperative outcomes and short-term results were compared between the groups.Results:The study included 101 patients (30 were obese). Sex (female: 35 vs. 37%, P=0.89), American Society of Anesthesiologists score (2 vs. 2, P=0.41), number of patients undergoing neoadjuvant chemoradiation (39% vs. 23%, P=0.12) and history of prior abdominal surgery (28% vs. 23%, P=0.62) were comparable between the groups. Operative time was longer in the obese group (311 vs. 332min. P=0.01). Overall complication rates (27% vs. 23%, P=0.72), length of hospital stay (6 vs. 7, P=0.10) and pathologic outcomes were similar between the groups. Conversion to laparoscopy was not required in any operation. Two nonobese patients required conversion to open surgery.Conclusion:Robotic rectal surgery for cancer in obese patients is equally safe and effective as in nonobese patients. The new robotic platform can facilitate to overcome obesity-related limitations of rectal surgery.