A bending operation device includes a bending operation lever, a wire pulling member, bending operation wires, and tubular members. The bending operation lever is tiltably supported to have an angle with respect to a longitudinal direction of an operation unit of an endoscope. The wire pulling member includes arm portions displaced in conjunction with tilt motion of the bending operation lever. The bending operation wires are connected to the arm portions. The bending operation wires cause bending motion of a bendable part disposed in an insertion section of the endoscope. A respective one of bending operation wires is inserted in each of the tubular members. The tubular members (i) change extension directions of the plurality of bending operation wires and (ii) guide the plurality of bending operation wires to the plurality of arm portions.