BACKGROUND The aim of the present study was to clarify the advantages of robotic-assisted laparoscopic lateral lymph node dissection (RALLD) for rectal cancer by comparing its short-term outcomes with those of open lateral lymph node dissection (OLLD) in a large series from a single center. In terms of RALLD for advanced lower rectal cancer, there are only a few reports with a small number of cases in retrospective, non-comparative studies. METHODS From April 2010 to July 2014, a total of 177 patients underwent rectal cancer surgery with lateral lymph node dissection. Four patients who underwent conventional laparoscopic lateral lymph node dissection were excluded. Thus, 173 patients were enrolled, with 85 RALLD and 88 OLLD cases. Perioperative outcomes, postoperative complications, and pathological results were compared between the groups. RESULTS No conversion to open surgery was necessary in the RALLD group. The rate of sphincter-preserving procedure was significantly higher in the RALLD group than in the OLLD group (p = 0.007). Operative time was significantly longer in the RALLD group than in the OLLD group (p = 0.007). Blood loss was significantly less in the RALLD group than in the OLLD group (p < 0.001). The rates of wound infection, small bowel obstruction, anastomotic leakage, and urinary retention were significantly lower in the RALLD group than in the OLLD group. Numbers of harvested lymph nodes and positive resection margin rates showed no significant differences. CONCLUSIONS The short-term outcomes of RALLD may be superior to those of OLLD for advanced lower rectal cancer.