The records of 46 patients with infective endocarditis diagnosed either clinically or post-mortem were analyzed. Twenty-six patients were over 60 years of age. S. aureus was the predominant organism, almost exclusively found in patients with acute endocarditis. Thirty-six patients had pre-existing heart disease, the most common being non-rheumatic valvular calcification and congenital defects. Two thirds of the patients, especially those with aortic valve regurgitation, developed new or progressive heart failure. A correct clinical diagnosis was established in only 30 patients. Twenty-three patients died, the mortality being 71% in acute and 32% in subacute disease. Only one of eight patients with prosthetic valve infection died. Four patients required urgent valve replacement. Early surgical intervention should be considered in patients with uncontrolled heart failure.