A ratchet screwdriver includes a mounting seat, a fixing ring, a control member, a driving shaft, four pawls and four springs. The mounting seat has a space, two first slots and two second slots. A passage is defined through the mounting seat. The first slots each have a first hole and the second slots each have a second hole. The driving shaft has a ratchet portion located in the space. The four pawls are biased by the four springs so as to be engaged with the ratchet portion. The fixing ring is connected to the mounting seat and the four pawls are pivotably connected to the fixing ring. The control member is rotatably mounted to the mounting seat and the driving shaft. The control member has two control plates to pivot the pawls to disengage from the ratchet portion of the driving shaft.