Abstract: A ratchet wrench includes a wrench head, a handle pivotally connected to the wrench head, a retaining member having retaining and actuating ends and movable longitudinally relative to the handle to engaging and disengaging positions so as to engage and disengage the wrench head, an actuating member movable transversely relative to the handle to first and second positions so as to move the retaining member to the engaging and disengaging positions, and a biasing unit disposed to bias the actuating member toward the retaining member longitudinally so as to ensure immobility of the actuating member in the first position.