The invention relates to a medical navigation marker device (1; 2; 3) comprising a light reflector, characterised in that the reflector features a marker pattern (11, 12, 13; 11, 12, 13, 14, 15, 16; 27, 28; 34, 37; 35, 37) having the following features:—the marker pattern (11, 12, 13; 11, 12, 13, 14, 15, 16; 27, 28; 34, 37; 35, 37) points in more than one spatial direction;—the marker pattern (11, 12, 13; 11, 12, 13, 14, 15, 16; 27, 28; 34, 37; 35, 37) comprises at least one moire pattern (11, 12, 13; 27; 37) which points in more than one spatial direction; and—the marker pattern (11, 12, 13; 11, 12, 13, 14, 15, 16; 27, 28; 34, 37; 35, 37) comprises a face identification pattern (14, 15, 16; 25, 26; 34; 35) which identifies the face of the marker being viewed from a particular spatial direction. The invention also relates to a combination of a medical marker device (1; 2; 3) and a medical navigation system (43) which uses the marker device (1; 2; 3) as a spatial position and/or orientation marker, and to the use of a medical marker device (1; 2; 3) for providing guidance to a user of a medical navigation system (43) by evaluating the spatial position and/or orientation information provided by the marker device.