Only a few physicians are willing to comprehensively concern themselves with how a legally watertight treatment documentation should be structured, in addition to their practical activities; however, the importance of the documentation cannot be emphasized enough, not only for a potential case of liability but also for the medical (further) treatment. This article therefore illustrates the legal foundations of the mandatory documentation and the most important questions associated with it for the practice, in particular on the content of the documentation, the timing of the documentation, the preservation of treatment documents and on the conduct in cases of an impending incident.