A method and apparatus for mounting a rear seat entertainment device easily and quickly on a seat of a vehicle without affecting the height adjustment of a headrest. The method includes the steps of preparing a bracket having an attachment portion for attachment with the seat and a mounting wall for attachment with a rear seat entertainment device, shifting a headrest upwardly to expose a headrest support tube and a flange of the support tube, placing the attachment portion of the bracket between the flange and a top surface of the seat in such a way that an opening of the attachment portion surrounds the support tube, attaching the rear seat entertainment device to the mounting wall of the bracket, and fixedly attaching a lower part of the rear seat entertainment device to the back of the seat.