Abstract: A mammographic phantom is disclosed having an orienting feature which permits the consistant placement of the phantom in the imaging plane of an X-ray beam. The phantom includes test objects which indicate the resolution capability of the X-ray system, as well as a step wedge which indicates X-ray beam quality. Consistant orientation permits the image of the test objects to be readily located on an exposed X-ray film and permits the step wedge to be accurately positioned adjacent the center of the X-ray beam to thereby reduce scattering affects.