Abstract: A safety latch for a cargo platform of the type particularly adapted to be mounted on the rear of a truck's cargo body. The cargo platform is pivotally mounted along its front edge to a combined elevating/storing mechanism which is of a chain and compounding sprocket type. In this type mechanism, the chain is taut as it holds the cargo platform in horizontal position when it functions as an elevator, and the chain is taut as it is compounded when it is desired to open and close the cargo platform between vertical storage and horizontal elevator positions. The safety latch cooperates with the cargo body, the chain, and the platform to insure that the platform is latched to the cargo body in its storage position when the chain is slack, i.e., not taut. The chain is always taut when the cargo platform is in the horizontal position and used as an elevator, as well as when the cargo platform is being swung between its elevator position and its vertical position.