Thus far, witnesses have played a crucial role in most proceedings before the International Criminal Tribunal for the former Yugoslavia. It can be expected that this will also be the case in the proceedings before the future International Criminal Court. The author of the note focuses on the position of witnesses and compares the rules, practices, and experiences of the Tribunal with the Rome Statute in this respect. In particular, the support and protection of witnesses and the role of the Victims and Witnesses Units of the respective courts will be discussed.