A ratchet wrench having a quick release structure includes a drive bar, a rotary head, and a locking switch. The drive bar includes a fork arm, a fork opening formed at the fork arm, an axial hole communicating with the fork opening, and a radial hole communicating with the axial hole. The rotary head is pivotally connected to two ends of the fork arm. The rotary head includes a round housing, a plurality of positioning recesses disposed on the round housing, and a pivot axis passing through the rotary head. The pivot axis is perpendicular to the radial hole. The locking switch includes a turning element disposed in the radial hole and a latch element disposed in the axial hole. The turning element rotatably drives the latch element to move axially, and the latch element is engaged with or released from any positioning recess.