When in 1995 members of the Aum Shinrikyo cult attacked Tokyo's subway system by releasing the nerve gas sarin, the world was shocked. It was the first usage of chemical warfare agents in a megapolis environment and a new shift in terrorism. Since then, and especially following the anthrax letters campaign accompanying the 9/11 incidents in the United States, the possibility of employment of weapons of mass destruction by terrorists of the future became more evident. In all CBRN plans, medical/hospital CBRN defence represents the weak link. State bodies tend to invest in operational aspects of CBRN operations while forgetting that medical consequences might last months or even years. On the other hand, the medical community in general is not very willing to be involved in such operations. A second problem is rooted within the administration attitude. If people in high places do not believe that new emerging threats pose a danger to the society, then it is extremely difficult to make a good plan. Problems identified during the 2004 Olympic Games in Athens regarding medical/hospital CBRN defence remained unsolved during the next Olympiad in China and are expected to be there during the London 2012 Olympic Games.