Abstract: An expanding file box includes a flat bottom panel and a pair of hollow side walls extending upwardly from each side of the bottom panel. The side walls have front and rear entrance openings leading into the interior thereof. The file box also includes flat front and rear panels connected to the front and rear edges, respectively, of the bottom panel to each pivot between a closed substantially vertical position and an open, outwardly tilted position. With the front and rear panels in open position, files or cards located within the box can be tilted relative to each other so that substantially the entire front face of the file is visible. The front panel includes a front sliding panel extending rearwardly from each side edge portion of the front panel to slidably extend into the hollow interior of a corresponding side wall to pivot with the front panel to form an extension of the side walls when the front panel is tilted in open position.