The case is reported of a 66-year old man who developed Streptococcus bovis endocarditis on a fairly loose aortic stenosis and who also presented with alcoholic cirrhosis complicated by an ultimately lethal hepatoma. On this occasion, comments are made on the following points: -Str. bovis is increasingly responsible for bacterial endocarditis. This micro-organism is now rapidly and reliably identified. -Str. bovis endocarditis has some clinical features of its own. -Patients in whom the usual portals of entry of bacterial infection (i.e. benign or malignant tumours of the colon or rectum) cannot be identified should be investigated systematically for hepatic cirrhosis. -Drug sterilization of the gut is useful to prevent bacteremia of intestinal origin in cirrhotic patients.