At the request of the Global Environmental Facility (GEF), its Scientific and Technical Advisory Panel (STAP) conducted a workshop to help clarify issues surrounding large-scale biofuel pro-grammes for the transport sector. The group, which convened in September 2005 in New Delhi, looked into the different families of biofuel technologies, their status, and the main issues surrounding their development prospects: costs, scaling-up issues, drivers for large-scale adoption, well-to-wheels energy balance and greenhouse gas emissions (on life-cycle analysis (LCA) basis), land-use, and agricultural practices. The discussions finally highlighted a number of controversial issues which require further detailed study and evaluation, such as those of potentials, international trade, policies and measures.