Background: According to the sociological analyses, in today’s societies, terrorism is one of the dire threats of the 21st century. The use of biological weapons, while rare, has a long history. Recently, the use of anthrax has been considered as one of the most dangerous biological threats. Materials and methods: This study was carried out by searching ‘bioterrorism,’ ‘anthrax,’ and ‘biological weapon’ as keywords in Google and PubMed data bases from 1990 to 2013. Results: Anthrax, a gram-positive bacterium, has typically been associated with three forms: cutaneous, gastrointestinal, and inhalational infection. Currently a fourth disease form has been reported (i.e. injectional anthrax) which is characterized by severe soft tissue infection and is prevalent among injection drug users. While cutaneous anthrax is the most common form of disease, vivid clinical scenarios and well-timed diagnosis can provide satisfactory outcome. Inhalational anthrax is the most fatal type of the disease. However, due to the similarity of the symptoms among patients with gastrointestinal, inhalational or injectional anthrax, they may have advanced infection at presentation. Once anthrax is suspected, the diagnosis can usually be made with gram staining and blood or tissue culturing followed by confirmatory testing (e.g. PCR). Although antibiotics are the mainstay of anthrax treatment, use of adjunctive therapies such as anthrax toxin antagonist, corticosteroids, mechanical ventilation and vaccination should be taken into consideration as well. Conclusion: Progress in detection, suitable vaccines, post exposure prophylaxis, infection control and decontamination are serious tools in fighting against the most powerful biological weapons. To assure that the public health and health care systems can respond to emergencies, the governments should provide medication stockpiles and improve the public health infrastructures in order to strengthen the emergency response system.