The robotic system for flexible endoscopy was first developed as a platform enabling tissue triangulation in natural-orifice translumenal endoscopic surgery (NOTES). Then endoscopic submucosal dissection (ESD) was introduced and has widely been employed for the treatment of early gastrointestinal carcinoma. Subsequently, endoscopists became well aware of the limitations of their endoscopic manipulations with the conventional flexible endoscopes developed for diagnostic use, which led to the development of robotic systems for upper/lower gastrointestinal tract endoscopes intended for therapeutic use. Most flexible robotic endoscopes have 2 mechanical arms attached to the head, allowing surgeons to perform endoscopic manipulations, such as grasping, traction, incision, excision, and hemostasis. However, there are still many challenges that remain to be addressed: the ideal robotic endoscope has not yet been realized. This article reviews the ongoing developments and our own efforts in the area of flexible robotic endoscopy.