Patients with infective endocarditis are frequently first evaluated in an emergency department at a time when clinical data are insufficient for a conclusive diagnosis. The records of 22 patients with proven bacterial endocarditis first seen in our emergency department were reviewed. The most common feature of the initial history was the presence of fever in 11 (50%). The most common physical finding was a heart murmur in 18 (82%). All patients had positive blood cultures. The most frequently isolated organism was Staphylococcus aureus. Pertinent clinical and laboratory data available on admission that enabled the emergency physician to suspect infective endocarditis were systemic manifestations of fever, malaise and arthralgias together with anemia, leukocytosis and hematuria.