Abstract: An improved apparatus for viewing agglutination of blood cells in test tubes utilizes magnetic force to hold a magnifying mirror in the desired orientation on the base portion of the viewer. The magnetically held mirror can be adjusted more quickly and easily than mirrors supported by mechanical clamping arrangements, as in previously available agglutination viewers. The improved viewer also includes an illumination source in the form of a lamp head which can be adjusted in position with respect to the base portion and magnifying mirror. In one embodiment, the lamp head is provided with illumination by means of a fiber optic cable enclosed in a flexible gooseneck-type conduit. The fiber optic cable receives light from an incandescent lamp or other light source housed in the base portion of the viewer. In a second embodiment, the lamp head contains an incandescent lamp and can be rotated about two perpendicular axes by means of an articulated structure connected to the base portion of the viewer.