One hand-size incision surgery (OHaSIS) is a surgery that is carried out through one hand-size incision with or without laparoscopy. Safety, feasibility and recovery advantage of the anterior resection of rectal cancer by the OHaSIS were studied. Nineteen consecutive patients with rectal cancer, consisting of seven rectosigmoid, six upper rectal, and six lower rectal cancers, were treated with anterior resection, including seven high, six low, three super-low, and three partial intersphincteric resections, through a suprapubic longitudinal one hand-size incision. The initial 11 patients were treated in combination with laparoscopy and the following eight patients were treated without laparoscopy. All anterior resections with mesorectal excision were completed in a safe manner with acceptable operative time (average 245 min), blood loss (average 280 g), and postoperative complications without any elongation of the initial incision. When compared with 12 previous high and low anterior resections by conventional open surgery (OS), the 13 high and low anterior resections by the OHaSIS showed equivalent operative time, blood loss, anastomotic procedures of single stapling, lymph node numbers dissected, surgical margin of the anal side of the tumor, and complications. Moreover, analysis of perioperative parameters for surgical invasiveness, including a body temperature >37 degrees C, days of bed rest, and days of use of parenteral narcotics, revealed a recovery advantage in the OHaSIS group compared with that in the OS group. These results suggest that anterior resection for patients with rectal cancer by the OHaSIS is safe, feasible, and less invasive than conventional OS, and has sufficient operative performance. Although the survival benefit and recurrence rate by this approach must be ensured in a future trial, we would like to propose the new concept of OHaSIS for treating rectal cancer.