ABSTRACT
A 26-year-old woman was referred to our hospital with a high fever and thrombocytopenia. The patient was initially given a diagnosis of disseminated intravascular coagulopathy and sepsis. Medial therapy with antibiotic and anticoagulative drug was started in the Department of Internal Medicine. After that, dermatologists identified painful nodular erythema on the face and extremities as Osler's nodes. Echocardiogram revealed a vegetation near the annulus of the mitral valve. The urgent operation was performed. Intraoperative findings showed vegetation on the posterior wall of the left atrium and normal mitral valves. Therefore, vegetation was completely excised with the diseased left atrial wall and the mitral valve was preserved. The defect of the atrial wall was repaired with a pericardial patch. Methicillin-resistant <i>Staphylococcus aureus</i> was detected by blood and tissue bacterial culture. Postoperative echocardiograms showed mild mitral regurgitation. The patient was discharged from hospital after an uneventful postoperative course.