List of parties to the Biological Weapons Convention

The list of parties to the Biological Weapons Convention encompasses the states which have signed and ratified or acceded to the Biological Weapons Convention (BWC), a multilateral treaty outlawing biological weapons.

On 10 April 1972, the BWC was opened for signature. The Netherlands became the first state to deposit their signature of the treaty that same day. The treaty closed for signature upon coming into force on 26 March 1975 with the deposit of ratification by 22 states. Since then, states that did not sign the BWC can only accede to it.

A total of 197 states may become members of the BWC, including all 193 United Nations member states, the Cook Islands, the Holy See, the State of Palestine and Niue. As of July 2024, 186 states have ratified or acceded to the treaty, most recently Tuvalu in June 2024.^[1] As well, the Republic of China (Taiwan), which is currently only recognized by 11 UN member states, deposited their instruments of ratification of the BWC with the United States government prior to the US's decision to switch their recognition of the sole legitimate government of China from the Republic of China (ROC) to the People's Republic of China (PRC). A further five states have signed but not ratified the treaty.

Several countries made reservations when ratifying the agreement declaring that it did not imply their complete satisfaction that the BWC allows the stockpiling of biological agents and toxins for "prophylactic, protective or other peaceful purposes", nor should it imply recognition of other countries they do not recognise.