Abstract: A grain hauler trailer comprising an under belly compartment in open communication with an upper compartment for receiving large quantities of grain therein and maintaining a low center of gravity for the trailer to facilitate movement of the heavy load along the highway, the trailer being pivotally mounted on a wheel truck assembly for facilitating fabrication of the trailer and unloading of the grain from the storage compartments. The upper compartment is closed by a plate member which may be utilized for supporting additional materials during transportation of the grain, and an access port is provided in the plate member for loading of the grain into the compartments. A discharge port is provided in the rear portion of the storage compartments for discharge of the grain therefrom as the trailer is pivoted to a substantially vertical position during the unloading operation.