In this review, the role of the fermentation process in mediating antibiosis in fermented foods will be examined. This will focus almost entirely on the lactic acid bacteria whose activity in fermented foods and whose biochemical and metabolic properties are well characterised. In addition, the range of different types of fermented products that are produced in different parts of the world will be briefly surveyed. The reader is directed to the excellent overviews in the text edited by Wood (1998) as a source of more detailed information on this topic. Fermented beverages are not within the scope of this review.