A through-door package delivery assembly is mountable in a garage door or other mounting door. A delivery door of the assembly is operably connected to an internal chute so that moving the delivery door to a delivery position moves the chute to obstruct access through the mounting door. When the delivery door returns to a blocking position, the chute angles downwardly to deposit a package on the floor inside the mounting door. The assembly is also able to be carried by a garage door when it opens without impeding operation thereof.