Effective biosecurity is an important requisite for the conservation of biodiversity. Preventing the introduction and spread of invasive species including pests, diseases and other organisms through biosecurity measures is important, not only for food security and agricultural health, but also links directly with the prevention of biodiversity loss. Although several international instruments are relevant in this regard, legal analysis of biosecurity at both the international and national levels remains limited. In light of the far‐reaching implications of biosecurity failures, there is an urgent need to recognize the nature of biosecurity and to understand how effective biosecurity frameworks can be developed. The present article seeks to contribute to this gap, first, by highlighting the nature of biosecurity as a regulatory concept; second, by providing an overview of some of the key international legal provisions and standards applicable to biosecurity; and, finally, by discussing some of the challenges which arise for the application of an international framework to biosecurity and the adoption of domestic biosecurity frameworks, particularly in the context of developing countries.