A fluid-operated torque wrench for tightening or loosening a fastener has a housing having two housing portions including a cylinder portion and a driving portion, cylinder-piston means arranged in the cylinder portion and movable along a first axis, a lever-type ratchet mechanism arranged in the driving portion and connected to the cylinder-piston means to be driven by the later, the lever-type ratchet mechanism having a ratchet turnable about a second axis which is perpendicular to the first axis, at least three connecting elements including first and second connecting elements receiving a given turning force acting in one direction during operation of the wrench, and a third connecting element receiving a turning force in an opposite direction during operation of the wrench and being equal to the given turning force acting in the one direction, so that one of the turning forces turns a fastener to be tightened or loosened while another of the turning forces is transferred to a stationary object.