Surgical procedures like endoscopy and hysteroscopy often require precise work in tight spaces within the human body. This includes tasks like observing, diagnosing, and cleaning. To handle these tasks, various surgical robots have been created. Besides the popular Da Vinci surgical system, there’s a growing interest in creating robots that cause less harm, known as natural orifice surgical robots. These robots need to be flexible, compact, and reliable. A tendon-sheath mechanism is a good fit for these requirements due to its flexibility. In this chapter, we discuss two examples of tendon-sheath surgical robots, covering their design, testing, and practical uses.