The link between health and environment has been acknowledged progressively in international declarations and agreements, from the Stockholm Conference of 1972 to the recent conference of the parties of CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora) calling for the integration of issues of livestock-wildlife-human-ecosystem health interface into the activities and resolutions of the major conservation multilateral environmental agreements (MEA). In line with the growing commitment to sustainable development, numerous international conferences and declarations and diverse legal instruments give an international legal framework to the issues related to health and biodiversity. In the meantime, as globalization is participating in the emergence or re-emergence of diseases, it appears the notion of global health governance along with the awareness that public health issues are linked with environmental factors. In this respect, international environmental law might be appropriate in fostering action at the international and regional level as it is its very nature to focus on the responsibility of the states to take into consideration their neighborhood. In Southeast Asia, the governments have become increasingly aware of the importance of the biodiversity conservation for human development and ecosystems health and the international documents are steadily translated through various paths into regional initiatives, legal instruments, and formal or informal engagements. This article aims to proceed backwards from the present to determine the main steps leading to the elaboration of the international instruments related to health and biodiversity and to present the ways they have been integrated and implemented at the regional level, in Southeast Asia.