1. An organ-region-indication system incorporated in an electronic endoscope system in which an endoscope image is displayed as a motion image on a monitor in accordance with a video signal produced therein, said indication system comprising: an organ-region-image data base, constituted on the basis of an organ map, in which a plurality of reference data indicating distinctive organ-regions of said organ map and a plurality of image data representing said distinctive organ-regions are correspondingly stored; a still-image-capturing system that retrieves a frame of still image data as referential image data from the video signal at suitable regular time intervals; a searching system that searches said organ-region-image data base for image data which coincides with said referential image data after the retrieval of the frame of still image data from said video signal by said still-image-capturing system; and a reference-data-display-control system that displays corresponding reference data on said monitor only when the image data, which coincides with the referential image data, is found by said searching system, whereby an endoscope image displayed as the motion image on said monitor is indicated by said corresponding reference data displayed thereon.