Abstract: A tailgate apparatus which automatically opens and closes a tailgate positioned at the rear of a tiltable truck bed of a dump truck. The tailgate is rigidly connected and orthogonally oriented to two spaced forwardly extending gate arms, the forward ends of which are preferably pivotally connected to adjacent the upper margins of the side walls of the truck bed. The tailgate thus moves arcuately upward from the closed position against the ends of the side walls and bottom by an elongated pivot arm which is pivotally connected at each end thereof between the gate arm, preferably each of two gate arms, and a stationary point of the dump truck near the truck bed transverse pivotal tilting axis as the truck bed is tilted. The entire tailgate will thus move manditorily upward arcuately to a position above the side walls to the degree that the truck bed is tilted so that the truck bed may carry and dump debris piled much higher than the side walls.