The BWC, the first multilateral disarmament treaty banning the production and use of an entire category of weapons, entered into force on 26 March 1975. Over the intervening years, increasing numbers of States joined the Convention, which currently has 165 States Parties. The BWC effectively prohibits the development, production, acquisition, transfer, stockpiling and use of biological and toxin weapons and is a key element in the international community's efforts to address the proliferation of weapons of mass destruction.

States Parties to the BWC have strived to ensure that the Convention remains relevant and effective, despite the changes in science, technology, politics and security since it entered into force. Throughout the intervening years, States Parties have met at five-year intervals to review the operation of the BWC. Between these review conferences States Parties have pursued various activities and initiatives to strengthen the effectiveness and improve the implementation of the Convention. The Seventh Review Conference of the Biological Weapons Convention will be held at the United Nations Office in Geneva from 5 to 22 December 2011.

Since the inception of the BWC, it has been recognised that to be truly successful, an international instrument must include amongst its members all the countries of the world. The BWC review conferences have regularly asserted that increasing the membership of the BWC is therefore of the greatest importance. The Chairman of the annual meetings of States Parties is charged with overseeing the membership drive, lobbying non-members to join, and reporting to States Parties on collective progress.

As early as the Second Review Conference in 1986 States Parties realised that enhanced transparency and information sharing would help reduce the occurrence of ambiguities, doubts and suspicions, in order to improve international co-operation in the field of peaceful biological activities. This prompted them to develop annual Confidence-Building Measures which included activities such as exchange of data on research centres and laboratories, exchange of information on national biological defence research, and active promotion of contacts between scientists, other experts and facilities engaged in biological research.

In 2006, a historic agreement was reached to create and fund an Implementation Support Unit (ISU) for the BWC. The ISU is made up of three full-time staff members, housed within the Geneva Branch of the United Nations Office for Disarmament Affairs. The ISU was officially launched on 20 August 2007 in a ceremony in Geneva, Switzerland. The unit is tasked with administrative, CBM-related, implementation and universalization functions. The ISU has also been mandated to support the Chairs of Meeting of States Parties in promoting universalization, to maintain a list of national points of contact for universalization; and to consolidate and make available information on progress in encouraging others to join the treaty.