The case is described of a 49-year-old woman who developed endocarditis in relation to the prosthetic valve two months after insertion of a Starr-Edwards mitral valve prosthesis. Initially Corynebacterium hofmanni was isolated from blood culture. Later, while the patient was receiving antibacterial chemotherapy, Candida albicans was also isolated and she was treated with 5-fluorocytosine. A cure was effected without the need for further valve replacement.