OBJECTIVES: Atrial fibrillation (AF) contributes for stroke, sudden death, heart failure, markedly reduced exercise capacity and degraded quality of life. Therefore, an effective treatment of AF is expected to reduce cardiovascular (CV) events and their costs. In 2010, dronedarone has been approved by Korean FDA for risk reduction of CV hospitalization in patients who are in sinus rhythm or who will be cardioverted with relevant conditions. The purpose of this study is to evaluate the cost-effectiveness of dronedarone compared with amiodarone in Korea. METHODS: We used the Markov simulation model for AF patients consisting with health states for AF treatment, off-AF treatment, symptomatic AF recurrences, stroke, acute coronary syndromes, congestive heart failure and death. Transitional probability was obtained from ATHENA trial and published literatures. Patient baseline, drug cost, initiation and monitoring cost of AF treatment, disease state cost and adverse event cost were obtained from national insurance claim database. The effectiveness of amiodarone vs. dronedarone was drawn from results of mixed treatment comparison. Discount rate for cost and effectiveness were applied as 5%. From the societal perspectives, we evaluated cost for life-year gained (LYG) and quality adjusted life-years (QALYs) until patients become 100 years old. Subgroup analysis and sensitivity analysis was performed to deal with uncertainty.  RESULTS: In the base case analysis, the incremental cost-effectiveness ratio (ICER) of dronedarone versus Amiodarone was approximately €2344/LYG (KRW 3.75 million, 1 Euro=1600 KRW). Results were robust across subgroups. The ranges of ICER in the sensitivity analysis were from around €1875 ~ €3750/LYG (KRW 3 to 6 million/LYG). Fifty percent of simulations in probabilistic sensitivity analysis fall below a willingness-to-pay of about €3750 per QALYs (KRW 6 million per QALYs). CONCLUSIONS: These results showed that dronedarone is to be cost-effective vs. amiodarone for AF patients in Korea.