A trash compactor for use within the box of an automotive garbage truck, comprising: (a) a pair of conveyors arranged in a V-shape laid on its side, the first conveyor being horizontal and supporting and moving a trash load from a trash loading area, through a trash compacting area, to a compacted trash unloading area, the second conveyor being inclined upwardly. A plurality of crushing plates are axially carried by rotatable shafts transversely of each conveyor, for crushing trash at the trash compacting area which is at the apex of the conveyors V-trough. The top run of the second conveyor transfers compacted trash from the compacted trash unloading area to a trash storage area within the box; wherein compacted trash will by evenly distributed within the box trash storage area of the garbage truck, for efficient use of available space.