Abstract: The side discharge bulk material trailer includes a frame with two I-beam members. A plurality of A-frame members are attached to the I-beams. A fore and aft extending tube is attached to the apex of each A-frame. Floor plates are attached the upward facing surfaces of the legs of the A-frames. A front wall and a rear wall are attached to the frame. Upper doors and lower doors are provided in the side walls. The lower doors have a lower edge pivotally connected to the frame for pivotal movement about a horizontal axis. The upper doors have a top edge pivotally attached to the end walls for pivotal movement about a horizontal axis. Hydraulic cylinders pivot the doors to open and closed positions. Locks retain the lower doors in a closed position. The lower doors hold the upper doors closed.