All cardiac surgical procedures performed in 79 German cardiac surgical units in the year 2004 are presented in this report, which is based on a voluntary registry organized by the German Society for Thoracic and Cardiovascular Surgery. A total of 100 830 cardiac surgical procedures (ICD and pacemaker procedures excluded) were reported to the registry for the year 2004, an increase by 1.1 % compared to the year 2003. More than 7.8 % of the patients were older than 80 years. Hospital mortality in 58 144 isolated CABG procedures (7.1 % off pump) was 2.8 %, and 4.5 % in 18 617 isolated valve procedures. This registry is an important tool of the German Society for Thoracic and Cardiovascular Surgery to allow a continuous and voluntary monitoring of quality and to illustrate the development of cardiac surgery in Germany.