SAOimage (pronounced S-A-0-image) displays astronomical images in the X11 window environment. It was written by Mike Van Hilst while he was at the Smithsonian Astrophysical Observatory (SAO) in 1990 and is now maintained by Doug Mink also at the SAO. Online documentation is available at http://tdc-www.harvard.edu/software/saoimage.html Online help is available at http://tdc-www.harvard.edu/software/saoimage.html. Image files can be read directly, or image data may be passed through a named pipe (Unix) or a mailbox (VMS) from IRAF display tasks. SAOimage provides a large selection of options for zooming, panning, scaling, coloring, pixel readback, display blinking, and region specification. User interactions are generally performed with the mouse, but keyboard alternatives are often available. The SAOimage desktop includes, a main image display window, a button menu panel, a display magnifier, a pan and zoom reference image, and a color bar. A color table graph window can be brought up by clicking on the color bar. Bugs or problems should be reported to Doug Mink at dmink@cfa.harvard.edu.