Reported here is a case of native valve infective endocarditis in which Staphylococcus lugdunensis was isolated from blood cultures as well as from the mitral valve. It is suggested that tube coagulase-negative staphylococci isolated from blood cultures of patients with infective endocarditis be considered carefully for possible clinical significance. The use of the ornithine carboxylase test as a simple screening method for identification of Staphylococcus lugdunensis is recommended.