Streptococcus constellatus infection is a rare cause of myocardial abscess. The complication of cerebritis is also rare. We report a case of S. constellatus bacteremia in a 21-year-old woman who developed fever and watery diarrhea 7 days prior to admission. Computed tomography of the brain showed severe effacement of the cerebral sulci, narrowing of the ventricular system, and severe brain swelling. Echocardiography showed a cystic lesion of about 2 cm(2) over the left atrium. Mannitol and dexamethasone were administered. Hyperventilation was performed. Intravenous penicillin G and ceftazidime were administered but without response. The increased intracranial pressure persisted despite medical treatment. She died 3 days after admission. Culture of cerebrospinal fluid grew S. constellatus and 3 sets of blood cultures grew S. constellatus. This case emphasizes the potential pathogenic role of S. constellatus in myocardial abscess.