This thesis examines organisations as mediators and how different kinds of organisations have different prerequisites to act as mediators. Global, regional and subregional organisations are often asked to mediate in conflicts, but considering the circumstances, who should mediate?In a mediating process the mediator should be considered as important an actor as the disputing parties and should hence be scrutinized as one. Mediation is a complex subject to study and theoretically the opinions differ on what characterises a good mediator. I have taken many of the different views in consideration and constructed a model from which organisations and their prerequisites can be compared and evaluated.