The global community of today is confronted with serious threats from infective diseases, which can appear as naturally-occurring diseases, outbreaks and pandemics, or after deliberate misuse of the pathogens in the event of bioterrorist actions. There are about 2-3 million of various microorganisms in the Nature, and only about 5% of them have been identified until now. In 2013 there were about 35 million people infected with HIV in 119 countries, and 1.5 million people died. The anthrax campaign of 2001 in the United States, as well as subsequent outbreaks of SARS, the avian flu and Ebola, along with the swine flu pandemic, show that microorganisms are a real threat with unforeseeable consequences for human health, the environment and society, and accordingly represent a serious security risk per se. Unlimited possibilities for manipulations that science and technology provide in this area instill fear of the possible abuse of the pathogens and their use in the war and bioterrorist acts, particularly in times of accumulated contradictions of modern civilization. Therefore, the development of co-operation strategies and precise definition of the roles and tasks of intelligence and security sector, police, military, public health sector and decision-makers in such circumstances as well providing of adequate resources for detection, identification, diagnostics and treatment of the agents and the diseases should be one of the main national tasks. International cooperation is also of paramount importance. This paper presents the experience and lessons from the large outbreaks that occurred in our geographic region in different historical periods: typhus, which caused great damage to Serbian army and people during World War I, the epidemic of smallpox in Yugoslavia in 1972 as the biggest postwar outbreak in Europe and the tularemia outbreaks in the area the former Yugoslavia in the 1990s. The infective agents causing these diseases are potential biological weapons.