The Gram-positive bacterium Listeria monocytogenes uses a wide range of virulence factors for its pathogenesis. Expression of five of these factors has previously been shown to be subjected to post-transcriptional regulation as a result of their long 5'-untranslated region (5'-UTR). We have investigated the presence of 5'-UTRs among the other known virulence genes and genes that encode putatively virulence-associated surface proteins. Our results strongly suggest that L. monocytogenes controls many of its virulence genes by a mechanism that involves the 5'-UTR. These findings further emphasize the importance of post-transcriptional control for L. monocytogenes virulence.