For laparoscopic anterior resection, an additional small incision is usually placed in the left lower quadrant or the suprapubic portion. As a left inguinal hernia incision is close to both the left lower quadrant and the suprapubic portion, such an incision can be used for anastomosis in laparoscopic anterior resection, without additional incisions. We report a laparoscopic anterior resection using a left inguinal hernia incision for colorectal anastomosis, in a patient who underwent concomitant left inguinal hernia repair. After a total mesorectal excision was performed laparoscopically, the distal portion of the rectum was transected by a stapler. A 4 cm skin incision was made in the left inguinal region and carried down to the peritoneum through the hernia sac. The bowel resection was performed extracorporeally, and an anvil was placed at the proximal end of the colon over a purse-string suture. After colorectal anastomosis was performed using a circular stapler inserted through the anus, the inguinal hernia was repaired with a mesh. The inguinal wound healed without surgical site infection, and the patient was discharged ten days after surgery.