Endocarditis due to Haemophilus paraphrophilus is an uncommon disease. We report a case of H. paraphrophilus endocarditis with embolic complications in which the causative organism was resistant to beta-lactam antibiotics. Before April 1994, 16 cases of H. paraphrophilus endocarditis had been reported. Infection by this organism usually affects a previously damaged mitral valve. We emphasize the fastidiousness of the organism and the high incidence of embolic complications, which determine the outcome. To our knowledge we describe the first patient with endocarditis due to beta-lactam-resistant H. paraphrophilus.