A 78-year-old Japanese man with a 5-day history of fever (∼38°C) and decreased appetite was admitted to our hospital. Transesophageal echocardiography revealed aortic valve vegetation. Streptococcus constellatus was detected from a blood culture. An antibiotic sensitive to this strain was administered for 6 weeks, and the patient has been well for 6 months without any sign of relapse. A review of all documented cases of infective endocarditis due to S. constellatus revealed nonspecific initial symptoms, especially coughing, and complications of abscess formation and septic embolisation. Clinicians should carefully consider the choice of antibiotic agents in the treatment of infective endocarditis due to S. constellatus, because penicillin-resistant strains have been documented in some cases.