Pathogenic bacteria have evolved sophisticated strategies to overcome host defences, to interact with the immune system and to interfere with essential host systems. We coin the term 'patho-biotechnology' to describe the exploitation of these valuable traits in biotechnology, medicine and food. This approach shows promise for the development of novel vaccine and drug delivery systems, as well as for the design of more technologically robust and effective probiotic cultures with improved biotechnological and clinical applications. The genetic tractability of Listeria monocytogenes, the availability of the complete genome sequence of this intracellular pathogen, its ability to cope with stress, and its ability to traverse the gastrointestinal tract and induce a strong cellular immune response make L. monocytogenes an ideal model organism for demonstrating the patho-biotechnology concept.