Abstract: A vision panel assembly for a fire door includes a frame structure and a glass vision panel which are mounted in a rectangular opening in the fire door. The frame structure includes a pair of frames which are anchored in grooves in the fire door and which are clamped against the glass vision panel. One frame is provided with fastener bars which are threadedly engaged by fastening screws for securing the frames together. Panel support elements extend through openings in the fastener bars for engaging edges of the glass vision panel to provide support therefor.