Erysipelothrix rhusiopathiae is recognized as the pathogen causing the skin lesions of human erysipeloid. This condition most often occurs as an occupational hazard of meat and fish handlers, veterinarians, laboratory staff, and others exposed to meat and fish products in industry and the home. The organisms occur in nature in putrefying and decaying matter and are commensals of the oropharynx of domestic animals, in fish slime and scales, in birds, rodents, and in more exotic creatures, including the kangaroo, wild bear, and mink (Woodbine, 1950).When pathogenic, the portal of entry is usually through a skin abrasion, though Fiessinger and Brouet (1934) have recorded septicaemia due to E. insidiosa following ingestion of infected salt pork, and Rowsell (1955) has demonstrated by experiments on swine that the oral route may play a role. In pigs infection is common either as a minor cutaneous form (swine erysipelas), or as an acute and often fatal septicaemia of chronic arthritis or endocarditis. Human infection is uncommon and almost always limited to the cutaneous form.Published accounts of endocarditis due to E. insidiosa are few and none appear to our knowledge in the British literature. Two recent isolations made from fatal cases of subacute bacterial endocarditis, diagnosed before death and confirmed at necropsy, are discussed in this record.