Introduction: Endoscopic submucosal dissection (ESD) of large tumors of the rectum is particularly challenging using colonoscopy or with laparoscopic instruments. More recently robotic assisted technique has been described. Case Presentation: We describe the first reported case of robotic transanal endoscopic submucosal dissection (RTESD) in Australia for a large circumferential laterally spreading tumor of the rectum using the da Vinci® Si system with the patient in the prone position. The case took 145 minutes and the authors found good manoeuvrability due to the intuitive nature of the robot’s endowristed miniaturised graspers. The prone position facilitated robot docking and reduced the external robotic arm clashing. This procedure was safely performed and the patient was discharged the following day. Colonoscopic follow up to one year revealed no recurrence of disease. Conclusions: RTESD in the prone position is safe and presents a feasible alternative for management of large rectal tumors. We also anticipate the technique to further improve with the advancement of robotic technology.