A process is provided for coating/decorating molded resin products having excellent waterproofing properties, which is able to simply and effectively reuse waste FRP. The surface of the molded resin product obtained by mixing, melting, and making mixture 8 containing wood-derived cellulose fine powder 3, resin-derived resin powder 7, and waste FRP 4-derived FRP powder 5 into a given form is coated/decorated. In the process for coating/decorating molded resin products, the surface of the molded resin product is subjected to UV coating/decorating, and after roughening, the surface is subjected to the UV coating/decorating again.