A wide-angle door viewer providing a large wide-angle outdoor view which can be zoomed and is readily perceptible without closely approaching the eyepiece, which comprises an optical lens barrel having relatively large diameter lenses in positions of reverse Galileo system, a mounting barrel for mounting the lens barrel to a door or the like, and a zoom barrel fitted slidably to the mounting barrel and having a relatively larger diameter eyepiece on which the large view is provided for direct but distanced observation.