OBJECTIVES: Since the beginning of 2004, the diagnosis-related-groups (DRG) are implemented in the reimbursement procedure for German hospitals representing a significant change for the hospitals economic situation. As an example for non-invasive treatment procedures in a German hospital, a prospective health economic study evaluated the treatment costs of community-acquired pneumonia (CAP) from the hospital’s perspective. Results of an interim analysis were published in 2003, now the final results of the study are presented. METHODS: Open, non-randomized prospective observational study from the perspective of the German hospital administration. In 11 study centres, 319 patients were enrolled. A process-cost-analysis was performed to determine the costs for the German hospital sector starting from the admission up to the discharge of the patient. The cost calculation comprises diagnostic and therapeutic measures, drugs, hotel costs and nursing. Both personnel costs and material costs were included. Acquisition of medical devices was not included into the analysis. RESULTS: The patients enrolled suffered from moderate to severe stages of CAP with a mean length-of-stay of 11.5 days (peripheral ward: 10.7; ICU 0.8). Mean costs per patient amounted to 1528€ (SD: 1011€). Most important cost-driving factors were hotel costs (640€) and nursing (554€). Drug acquisition cost resulted in 201€, whereas costs for diagnostics (80€) and therapeutic measures (54€) were comparatively low. The most often applied drugs were macrolides (37.6% of the patients), ß-lactamase inhibitor-aminopenicillin combinations (32.3%), and cephalosporins of 2nd (30.4%) and 3rd generation (28.5%). Thirty-six patients (11.3%) died during the hospital stay. CONCLUSIONS: In hospitalised CAP, length of stay determines the costs from the economic perspective of the hospital, which underlines the importance of a reduction of length of stay in this indication. The need for rapid and safe antibiotic treatment becomes evident especially under consideration of the DRG reimbursement system.