Sudden death due to cardiac arrest represents one of the greatest challenges facing modern medicine, not only because of the massive number of cases involved but also because of its tremendous social and economic impact. For many years, the magic figure of 1 per 1000 inhabitants per year was generally accepted as an estimate of the annual incidence of sudden death in the industrialized world, with a survival rate of 6 %. This estimate was based on large numbers of published reports of local, regional, national and multinational experience in the management of cardiac arrest. Measuring the global incidence of cardiac arrest is challenging as many different definitions of patient populations are used. Randomized controlled trials (RCT) provide insights into the value of specific treatments or treatment strategies in a well-defined section of a population. Registries do not compete with clinical studies, but represent a useful supplement to them. Surveys and registries provide insights into the ways in which scientific findings and guidelines are being implemented in clinical practice. However, as with clinical studies, comprehensive preparations are needed in order to establish a registry. This is all the more decisive because not all of the questions that may arise are known at the time when the registry is established. The German resuscitation registry started in May 2007 and currently more than 230 paramedic services and hospitals take part. More than 45,000 cases of out-of-hospital cardiac arrest and in-hospital cardiac arrest are included. With this background the German resuscitation registry is one of the largest databases in emergency medicine in Germany. After 5 years of running the preclinical care dataset was revised in 2012. Data variables that reflect current or new treatment were added to the registry. The postresuscitation basic care and telephone cardiopulmonary resuscitation (CPR) datasets were developed in 2012 and 2013 as well. The German resuscitation registry is an instrument of quality management and a research network. The registry documents the course in patients who have undergone resuscitation at the time points of first aid, further management and long-term outcome and it can therefore provide a complete presentation of the procedures carried out and the quality of the outcomes. In addition, important scientific questions can be answered from the database. For example, a score for benchmarking the outcome quality after out-of-hospital resuscitation, known as the return of spontaneous circulation (ROSC) after cardiac arrest (RACA) score, has been developed. The registry is available for all emergency medical services (EMS) and hospitals in Germany and other German-speaking countries.