Two major issues encountered in the surgical resection of low rectal cancers (tumor located <6 cm from anal verge) are tumor-free surgical resection margin and adequate fields of colo-anal pull-through anastomosis. The clinical consequences of ensuring gross tumor-free surgical resection margin by transanal inside-out rectal resection technique were assessed for ultra-low rectal cancer patients. From February 2009 to September 2011, ultra-low anterior resection with a new method of eversion of the rectum through the anal canal after resecting the distal rectum and colo-anal anastomosis extracorporally performed in 30 patients (age range, 41-80 years) was reviewed. All patients received preoperative neoadjuvant concurrent chemoradiotherapy (CCRT) before the surgical resection. The median operating time was 265 min (range, 220-400 min), and the median intraoperative blood loss was 325 ml (range, 80-855 ml). No in-hospital mortality was noted among these patients. R0 resection (tumor-free margin range, 0.9-2.5 cm) was confirmed in all patients by pathologic reports, except one patient with 0.5 cm tumor-free margin. The new surgical technique of transanal inside-out rectal resection and colo-anal pull-through anastomosis for selected patients with ultra-low rectal cancers seems to be a safe and alternative procedure.