Listeria monocytogenes is an uncommon cause of illness in the general population. However, this bacterium is an important cause of severe infections in neonates, pregnant women, the elderly, transplant recipients and other patients with impaired cell-mediated immunity. Various clinical syndromes due to L. monocytogenes have been described such as sepsis, central nervous system infections, endocarditis, gastroenteritis and localized infections. A review of the clinical presentation of listeriosis is given in this paper. (C) 2003 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.