An endoscope bending portion includes a circular cylindrical member 20, a protrusion portion 60 that is formed protruding on an inner circumference of the circular cylindrical member 20, on a distal end side, and on which a wire hole 60h is formed, a pulling wire 40u that has a maximum outer diameter portion 41u formed at a distal end portion, and that is inserted through the wire hole 60h to have the maximum outer diameter portion 41u engaged with at least a part of a distal end surface 60s of the protrusion portion 60, and a restriction portion 60a that restricts inward movement, in a radial direction K, of the maximum outer diameter portion 41u engaged with the protrusion portion 60.
