Salmonellae are widely distributed but nomenclaturally controversial pathogens of both humans and animals. Despite elaborate studies, much still remain to be discovered about these organisms. Although Salmonella nomenclature has proved to be rather complex, in 2005, Salmonella enterica finally gained official approval as the type species of the genus Salmonella. In addition, one other species has been approved and recognised in the genus Salmonella, namely, Salmonella bongori. New serovars (serotypes) are continually being discovered each year and reported in the journal Research in Microbiology. Salmonella serovars and their antigenic formulae are listed in the White-Kauffmann-Le Minor scheme and updated by the World Health Organization’s Collaborating Centre for Reference and Research on Salmonella at the Pasteur Institute, Paris, France.