Enterohaemorrhagic Escherichia coli (EHEC), first identified as a human pathogen in 1982, is today recognized as a significant food borne hazard in many countries around the world. Infection often leads to haemorrhagic diarrhoea, and occasionally to kidney failure and death. Outbreaks of EHEC infections have occurred and continue to occur throughout many regions of the world with ruminants, particularly cattle, being considered the main reservoir. The primary source of EHEC is animal faeces and a range of commodities have been implicated in EHEC infections and illnesses. Globally, the consumption of beef, including ground beef and processed beef products, dairy products and fresh produce are among the most important sources of food borne EHEC infection. Managing this hazard in the food chain remains a challenge for many countries. Numerous risk assessments have already been undertaken and this report reviews those, providing guidance on how they can be used and their value in undertaking further risk assessment work in this area. A stronger linkage between risk assessment activities and risk management challenges and objectives is an important element of successfully addressing this problem. This volume and others in this Microbiological Risk Assessment Series contain information that is useful to both risk assessors and risk managers, including international scientific committees, the Codex Alimentarius Commission, governments and food regulatory agencies, scientists, food producers and industries and other people or institutions with an interest in the area of microbiological hazards in foods, their impact on human health and food trade and their control.