Adults with the ability to make decisions can only give consent in clinical trials of medical products themselves. For adults without the ability to make decisions, only the legal representative can give consent on behalf of the patient. In the case of minors, the (additional) consent of the legal guardian must be obtained for clinical trials of medical products, regardless of their decision-making ability. In intensive care- and emergency medicine-related research, it is not uncommon for patients to have lost their decision-making ability due to their medical condition. Therefore, when research within this vulnerable collective is intended, the procedures to obtain medical consent must be precisely defined within the study protocol, and appropriate information and informed consent forms for the respective addressees of informed consent should be prepared. This article intends to provide a practical overview of the most important aspects when obtaining medical consent in clinical trials of medical products. In addition to the uniformly applicable law in the European Union, this article takes further only the national legal situation in Austria into account.