OBJECTIVES: The objective of this study is to examine the economic outcome of Methicillin resistance in Staphylococcus aureus bacteremia in Korea, where MRSA is endemic in majority of hospitals. METHODS: We conducted retrospective case-control study of patients admitted to three university-based teaching hospitals in Seoul, Korea in 2005. Cases were defined as patients with Methicillin-resistant S. aureus (MRSA) bacteremia and controls were Methicillin- susceptible S. aureus (MSSA) bacteremia selected according to a priori matching criteria. 58 cases and 58 controls were identified. Hospital charges were collected from hospitals' billing system. RESULTS: The median hospital charge after the development of bacteremia was higher for cases with MRSA bacteremia ($8245) than for controls with MSSA bacteremia ($6569). The median hospital charge for pharmaceuticals of MRSA bacteremia patients was $2411 and that of MSSA bacteremia patients was $1289. The median length of hospitalization after the development of MRSA patients who survived was 32.5 days and that of MSSA bacteremia control patients who survived was 18 days. CONCLUSION: Antibiotic resistance in Staphylococcus aureus bacteremia increased direct medical cost by 26%. The results of this study indicate that the MRSA infection is associated with increased medical cost and prolonged hospital stay.