The epidemiological characteristics of infective endocarditis in France were established in a one-year survey of strictly defined cases. The incidence of the disease is 18 cases per year and per million inhabitants, i.e. 970 cases annually. Patients are generally treated in Teaching Hospitals (80% of the cases were at the end of the hospitalization period). The predominant pathogens are the streptococci non groupable in 40.4% of the cases (group D in 21.9%) and the staphylococci (20.8%). Patients with group D streptococci endocarditis are the older ones (mean age: 60 years). Staphylococcal endocarditis occurs in younger patients (mean age: 43 years), especially after cardiac valve prosthesis or unrecognized cardiac valve disease, and it is the most serious form, with a 45% mortality rate (overall mortality rate: 21%). One quarter of the patients undergo a surgical operation.