A ratchet wrench includes a head with a ratchet wheel, a first pawl unit and a second pawl unit received therein. The first pawl unit includes a first pawl and a second pawl, and the second pawl unit includes a third pawl and a fourth pawl. The first and second pawl units are controlled to be engaged with the ratchet wheel so as to provide sufficient number of teeth to be engaged with the ratchet wheel. The ratchet wrench outputs sufficient torque with a small angle of rotation.