Endocarditis as seen today differs significantly from that outlined by Sir William Osler in his famous Gulstonian lectures in 1885. The median age of the patients has increased; the spectrum of predisposing cardiac lesions has changed; more cases are due to unusual organisms, including gram-negative bacteria and fungi; and more cases present acutely and the classic findings of late endocarditis are seldom seen. Endocarditis was untreatable and uniformly fatal in 1885. Although continued advances in medical and surgical therapy have significantly increased survival, the recent appearance of multiresistant organisms in some cases is reminiscent of the Osler era. Recent advances in the diagnosis and management of endocarditis include the identification of a specific Staphylococcus aureus receptor protein on endothelial cells, better imaging of the cardiac structures using transesophageal echocardiography, improvement in clinical diagnostic criteria and surgical techniques, and the use of outpatient oral antibiotics for penicillin-sensitive streptococcal endocarditis.