Personal names play an important role in the medical language. Medical terms often consist of eponyms. A lot of expressions like ziekte van Basedow, ziekte van Hashimoto, syndroom van Down, Achillespees or doppleronderzoek are permanent ingredients of medical vocabulary. The eponyms can substitute long and complicated descriptions of medical terms. For specialists they have a clear meaning but on the other hand eponyms can cause confusion if there are used by people who have no medical education. An eponym can have two different meanings and the same illness can be described by two different persons what independently happens. What is the structure of an eponym? There are a lot of possibilities of naming an illeness, a syndrome or a part of body with an eponym. In many cases diseases, instruments or another medical units have been named after their discoverers or describers. This paper presents eponyms who have been collected from the Dutch medical press. They have been analysed in respect of their morphology and semantics, and have been splitted into groups.