A 65-year-old man was admitted with ataxic gait and high fever. Brain magnetic resonance imaging (MRI) showed multiple cerebral hemorrhages and echocardiogram showed vegetations attached to the mitral valve and moderate mitral regurgitation. No microorganisms were identified by blood culture examination. Despite adequate treatment with antibiotics, large multiple splenic abscesses were detected by computed tomography (CT), the patient complained of fever and the value of CRP was increased again. We decided to first perform splenectomy, followed by mitral valve repair and maze operation. The pathology of the spleen showed findings consistent with large abscesses due to septic emboli. The postoperative course was uneventful.