Abstract: A rain gutter shield preferably having (a) an elongated layerless screen of porous, non-woven polymeric fiber material and (b) two elongated semi-rigid ribs on each lateral edge of the screen. One of the ribs may have a header portion thereon sized to fit under the shingles on the roof of the building on which the rain gutter is mounted. Alternatively, each rib may have a channel formed in the lateral edge of that rib which is not attached to the elongated layerless screen so that the channels snap fit over the edge of a rain gutter. The method of installation may involve not only the use of the preferred rib structure, but also simply gluing or bolting one lateral edge of the elongated layerless screen to the lip of the rain gutter most distant from the building to which the rain gutter is mounted and, then, attaching the other lateral edge of the elongated layerless screen to the roof of that building.