A change speed pedal mechanism for controlling a transmission of a working vehicle comprises a first pedal pivotable on an axis extending transversely of a vehicle body, and a second pedal disposed adjacent the first pedal and pivotable on an axis extending longitudinally of the vehicle body. The first pedal is connected to the transmission such that its depression shifts the transmission in a forward accelerating direction. The second pedal includes a linkage arm extending to a position under the first pedal. When the second pedal is depressed, the linkage arm lifts the first pedal, thereby shifting the transmission in a backward accelerating direction.