A sudden acceleration prevention method for a vehicle includes the following steps, which may be performed by a controller: monitoring an output signal of an accelerator pedal sensor so as to obtain a detected operation state of an accelerator pedal, determining whether the detected operation state of the accelerator pedal is within a predetermined brake pedal operation range, determining whether the detected operation state of the accelerator pedal is within a predetermined accelerator pedal and brake pedal overlapping operation range if the detected operation state of the accelerator pedal is within the predetermined brake pedal operation range, and outputting an output reduction control signal of the vehicle if the detected operation state of the accelerator pedal is not within the accelerator pedal and brake pedal overlapping operation range.