Introduction Out of the 14.836 deaths for cardiac diseases in 2001, 1.945 was classified as sudden cardiac death. Several studies proved that Automated Internal Cardiac Defibrillator (AICD) is the preferred therapy in this group. The aim of the study was to evaluate the in-hospital costs for patients receiving an AICD implantation in Belgium in 2001. Methods Retrospective analysis of data from the national hospital registration system (MKG) was performed. Results 1.528.852 hospital admissions were registered, 196.675 with a cardiovascular disease. Of this group 485 was admitted for implantation of an AICD, 94% were diagnosed with a cardiac dysrhythmia. The mean age was 64 years (+/−13).The mean hospital stay was 12 days (+/−12), 47 % was admitted to the ICU with a mean length of stay of 7 days (+/−7). 34% were readmitted within the same year. The mean cost per stay was €11.500 with a surplus of €19.562 for the device and €2.638 per lead. Conclusion AICD therapy is an effective but an initially expensive therapy. This underlines the importance of screening and elaborating patient selection criteria.