An accelerator pedal assembly comprises a pedal arm, a pedal shaft, a return spring and a frictional force generating mechanism for generating frictional force according to movement of the pedal arm. The frictional force generating mechanism has a sliding guide path defining a sliding surface for generating frictional force and a frictional force varying mechanism located within the sliding guide path for varying frictional force according to movement of the pedal arm in such a manner that the frictional force generated when the pedal arm moves towards the position of maximum depression increases according to the amount of movement, and the frictional force generated when the pedal arm moves towards the rest position is reduced according to the amount of movement. This enables the assembly to be made smaller and means that the accelerator pedal assembly operates more smoothly as a result of superior depression force hysteresis.