The recent worldwide commercialisation of genetically modified organisms (GMOs), called also living modified organisms (LMOs), has raised questions and concerns over their potential impact on human health and the environment. Already before that commercialisation, many countries have adopted domestic biosafety regulations or guidance. They aim at evaluating and managing risks to ensure the safe transfer, handling, use and disposal of GMOs and their products.However, there are currently no binding international agreement addressing situations where GMOs are transferred across national borders.The need for such an international instrument was recognised for the first time during the negotiations of the Convention on Biological Diversity (CBD). This led to the establishment an Open-ended Ad Hoc Working Group on Biosafety (BSWG).The BSWG met six times between July 1996 and February 1999, where it developed draft text for a protocol on biosafety. The protocol is intended to address the transfer of LMOs from one country to another through a system of advanced notification and consent. The protocol was supposed to be finalised and adopted in February 1999. However, the timetable for concluding the protocol has been extended until January 2000 because of the present difficulty to reach agreement on some core issues, relating in particular to the potential trade and economic impacts of the protocol and the relationship between the protocol and the World Trade Organisation.Even if, because of its specificity, the protocol can be considered as a "curiosity" compared to other topics covered under the CBD, the experience which can be derived from the negotiations and the possible implementation of the protocol will clearly influence the discussion of other multilateral agreements negotiated in the framework of the Convention.