A pedal assembly comprising for driving a vehicle, comprising: a brake pedal (10) borne vertically swingably by a brake arm (11); a laterally biased accelerator lever (20) arranged just above the right-hand side of the brake pedal while being urged toward the brake pedal and having a lateral reciprocating stroke; and a guide roller (16) arranged at the right-hand portion of the brake pedal while having its circumferential edge protruded above the pedal. Further comprised is a spring (12) disposed on the floor of the vehicle below the brake pedal for urging the lower end portion of the brake pedal to this side. The accelerator lever is arranged, when in a non-load state, at an inclination with respect to the axis of the brake pedal.