Authors have previously proposed a process for recycling waste GFRP. In this process, porous glass fiber reinforced ceramics were produced by mixing clay and the crushed waste GFRP, and then firing the mixture (1). In this paper, the bending strength of tiles produced using the waste GFRP such as the sprue and runner produced in the injection molding was examined. From the results, it was clarified that the porous tiles reinforced by glass fibers had high strength. In addition, the relationship between the strength of tiles and the mixture ratio of clay and resin was clarified. On the basis of the experimental results, the equation which can estimate the bending strength of the porous tiles reinforced by glass fibers was proposed.