A ratchet wrench includes a wrench body, a ratchet assembly and a C-ring. The wrench body has a driving head at one end. The driving head has a cavity therein and a retaining groove defined in an inner periphery of the cavity. The ratchet assembly is mounted in the cavity of the driving head. The C-ring is configured to retain the ratchet assembly in place and defines an outer portion and an inner portion. The C-ring has two free ends, and at least one of the two free ends has an oblique face with a pointed edge towards an inside of the C-ring, which is allowed to pry the C-ring moving inward to be detached.