In 2025, we commemorated the 50^th anniversary of the ratification of the Convention on the Prohibition of the Development, Production and Stockpiling of Bacteriological (Biological) and Toxin Weapons and on their Destruction (Biological Weapons Convention, BWC). By 2025, 189 countries had signed the treaty, including the four original signatory states. However, research on microorganisms or their products – toxins – that can be misused for military or terrorist purposes is still being carried out in military facilities in many countries. For this reason, constant attention should be paid to the issues related to the individual Articles of the convention. This article, taking advantage of this anniversary, seeks to provide a precise definition of biological weapons, a brief historical overview of the use of biological agents in armed conflict, and a brief description of the efforts to prohibit the use of microorganisms or their products as weapons of mass destruction, especially against human targets. In its concluding remarks, given the overlap between biomedical and military research on the use of biological agents. The text addresses the still not completely resolved issue of the misuse of biological agents, referring to the long and layered history of their use for nefarious purposes, contributes to distinguish between defensive and offensive biological research, and draws attention to the complexity of issues related to the biological security of world´s states.

Keywords: Biological Weapons Convention; biological agents; biological warfare; history