Abstract: In apparatus for stacking flat articles such as flattened bags, two spaced rotatable hubs carry radial transfer arms provided with suction nozzles. By perforations on one side of the articles, the latter are collected up to the desired stacking height on prongs provided at one side of endless conveying members of an intermittently operative conveyor. The other sides of the articles hang over the other side of the conveying members where the latter are provided with supporting frames or plates which project laterally beyond the conveyor and are mounted at their central region on two parallel pivot shafts which are secured to the coveying members, extend transversely thereto and are spaced apart sufficiently to enable them to pass over direction-changing drums or wheels of the conveying members.