The FAO has been working on various aspects of biotechnology including genetically modified organisms (GMOs). In the area of a food safety assessment of GMOs, FAO and WHO have recently embarked in the development of international principles and guidelines for the safety assessment of plant GMOs in the framework of the Intergovernmental Codex Task Force for Foods derived from Biotechnology. The scientific input for the development of these principles and guidelines was provided by a series of Joint FAO/WHO Expert Consultations on Foods derived from Biotechnology. This review provides a general overview of the work carried out so far, including the results of the expert consultations and the present situation of the discussions in the Intergovernmental Codex Task Force.