OBJECTIVES: The treatment of surgical site infections (SSI) is associated with high costs for the statutory health insurance (SHI) and for hospitals. The DRG-reimbursement for septic revisions seems to be not cost-covering for hospitals. Without an Arthroplasty Register for Germany, exact numbers for SSI in hip arthroplasty and knee arthroplasty are not available. Also there is no approximation for the financial impact, yet. The purpose of this work is to estimate the financial impact and possible risk of SSI in knee and hip arthroplasty for SHI and hospitals. METHODS: To estimate the number of SSI for Germany, a projection for all SSI in primary hip and knee replacements in Germany (N=372.851) was made with data from the KISS module surgical (“Krankenhaus-Infektions-Surveillance-System”). Two approaches were used to assess the costs: First, treatment expenses from the Barmer GEK-report were used and second a bottom-up analysis based on the medical and pharmaceutical costs of the treatment algorithm for SSI. RESULTS: The revision treatment of SSI resulted in a financial burden of at least € 22.407.350 for hip replacement and € 13.760.280 for knee replacement for the SHI. Due to the even higher medical and pharmaceutical costs for the treatment of SSI in hospitals, SSI can cause a financial loss to them. CONCLUSIONS: To achieve a cost-covering treatment of SSI in hospitals, the several methods of reducing the risk of SSI should be checked with a cost-minimization-analysis. Then, hospitals have the opportunity to calculate the risk of higher SSI-rates against higher costs for primary replacement with a reduced risk of SSI. For the SHI a cost-benefit-analysis could be helpful to make a decision about requirements on methods used in primary replacement in hospitals to reduce the rate off SSI. A German Arthroplasty Register should include the collection of SSI data in its dataset.