To easily acquire an image of a tip end portion of a surgical instrument attached to a manipulator arm even when the surgical instrument is bent, a surgical system includes manipulator arms, a manipulation unit, and a controller. The manipulator arms include: a first manipulator arm including an instrument holder holding a first surgical instrument including an instrument bendable portion; and a second manipulator arm including an instrument holder holding an endoscope assembly including an endoscope bendable portion and a camera at a tip end portion of the endoscope assembly. A method of controlling the surgical system controls the endoscope assembly such that the endoscope assembly is bent so as to follow bending of the first surgical instrument that is bent based on an operating command.