A medical referencing device for a medical navigation system is provided, with which a movement of a body part, with the referencing device attached thereto, is trackable in space. The referencing device has a fastening device for fastening the referencing device to the body part and a referencing body which extends over a surface and is elastically stretchable in at least one direction. The referencing body is adaptable in shape to a contour of the body part and has a marking area with a pattern. The referencing body being configured such that during movement of the body part at least a section of the pattern is undeformed or substantially undeformed, and at least a section of the pattern is usable by the navigation system as reference for tracking the body part. A medical navigation system and a method for tracking a medical referencing device in space are also provided.
