Adult onset Still’s disease (AOSD) is an uncommon disorder of unknown cause. The clinical symptoms of AOSD are a spiking fever, a typical rash, arthralgia or arthritis, sore throat, lymphadenopathy, and splenomegaly. Pleuropulmonary and cardiac involvement are rare. We report a patient with a two-year history of AOSD with myocarditis refractory to cyclosporine and glucocorticoid. Significant congestive heart failure due to left ventricle dysfunction and hyperferritinemia developed during the hospital course. After therapy with etanercept, the patient’s clinical manifestations recovered and she regained normal left ventricular systolic function.