A bending operation device 70 includes a bending lever 45 that is tiltably supported with an angle to a longitudinal direction of an operation section 3 of an endoscope 1, a wire pulling member 54 that includes a plurality of arm portions 54b that are displaced according to tilting motion of the bending lever 45, a plurality of operation wires 65a to 65d that are connected to the plurality of arm portions 54b and that bend a bending portion 7 provided in an insertion section 2 of the endoscope 1 according to displacement of the wire pulling member 54, and a plurality of pulleys 68a to 68d that guide the plurality of operation wires 65a to 65d to the plurality of arm portions 54b, with the plurality of operation wires 65a to 65d being substantially parallel to one another, when the bending lever 45 is in a neutral position at which the bending portion 7 is substantially straight.