The study of 1527 autopsies showed that in 2% of cases the cause of death was Infective Endocarditis (IE) (acute in the absolute majority), mostly not diagnosed due to fulminant disease or to the short hospital stay and in some cases not correctly treated. Sepsis was correctly diagnosed in 12 patients (9 of whom were i.v. drug addicts) and was not identified in 14 patients (12 of whom had acute disease) who were diagnosed as suffering from CNS disease or pneumonia. Systematic autoptic study of patients with or without IE appears to be a very useful method to determine correctly IE mortality.