This paper presents a brief description of each of the main types of fiberboard used in the automobile. It covers typical applications for fiberboards with detailed information only on the interior trim parts. Applications where fiberboard and plastics compete are discussed. Also included are the advantages and disadvantages of fiberboards. The effect of humidity changes on fiberboard resulting in dimensional changes and warping tendencies in the fiberboard are explained with illustrations which emphasis the need for proper fastening of fiberboard and a method of measuring war-page. Test methods, performance testing, and possible future applications are discussed.