The right to decide about one's own body, health, and thus his live itself, may appear self-evident and not restrictable at first glance. On closer examination, however, there are numerous situations in which this right – its legal nature shall be discussed later - cannot be exercised directly by oneself, perhaps because he cannot do so due to his age or his lack of capacity to act in the situation. Such situations regularly arise in the course of medical treatment and surgical intervention on minors or immature adults, especially when it cannot be expected to receive the approval from the patient, e.g. when he is unconscious. In view of such cases it is necessary to explore the possibilities of a statutory right of representation and their scope and to discuss, who can or cannot act in representation of the patient and what effects should be emitted by the legal representatives declaration, but also what measures the law provides for the protection of the person concerned. Finally, the limits of the legal right of representation shall be discussed.