Fimbriae are thin, proteinaceous surface organelles produced by members of the Enterobacteriaceae, including most salmonellas. A number of fimbrial antigens expressed by strains of Salmonella enteritidis and S. typhimurium have now been described and characterized. However, their functions are still poorly understood, although some evidence indicates they have a role in bacterial survival in the host or external environment. Diagnostic tests based on the detection of fimbriae or specific antibodies against them have recently been developed and applied successfully to the rapid and specific identification of S. enteritidis infections. The role of salmonella fimbriae in future generations of live vaccines either as protective antigens or as the carriers of heterologous antigens is also discussed.