An image transformation apparatus for a vehicle rear monitoring device uses a transformation table to transform an image of the rear of a vehicle captured by a camera mounted on the vehicle for capturing the rear of the vehicle into an output image assumed to be obtained by capturing the rear at a predetermined inclination from a virtual camera position different from an actual camera position at which the camera is mounted, and displays the output image on the monitor 4. Furthermore, the output image may be displayed on the monitor 4, with a steering start guideline, a steering amount guide mark, a vehicle width guideline, and a vehicle path guideline superimposed thereon.