A paint guard for protecting a stair covering during the painting of a skirtboard on a staircase, the paint guard having a plurality of interconnected and generally perpendicular planar surfaces, including a surface for covering a portion of a stair tread, a surface for covering a portion of a stair riser, and a plurality of surfaces for covering the edges of the stair covering nearest the skirtboard. The paint guard also includes a concave portion attached to the surface for covering a portion of a stair tread, the concave portion covering a forward edge portion of a staircase tread. The paint guard is either rigidly made or constructed of a durable material that can be bent and folded into the final shape, and is adjustable in size to fit on staircases of varying dimension.