A positioning structure for a ratchet wrench contains a ratchet wrench including a driving head, a receiving cavity, a first groove, a second groove, and a hole. The receiving cavity has a driving member, and the driving member having a toothed portion. The first groove has two opposite retaining blocks each having a plurality of locking teeth so as to engage with the toothed portion and having an orifice and a receiving aperture, and between two receiving apertures is defined a first resilient element. The second groove has a directional control member mounted, and the directional control member has a limiting portion, a recessed portion, an actuation portion, and a shaft, wherein a second resilient element is fitted onto the shaft and is inserted into the hole of the second groove, and the actuation portion is inserted into two orifices of the two retaining blocks.