Bioenergy—that is, biofuels of biological and renewable origin, like bioethanol, biodiesel, and biomass for energy—is the subject of increasing attention around the world. Oil prices have climbed to unprecedented heights, and concerns about the environmental effects of fossil fuel use are on the rise. Bioenergy appears to offer hope for addressing these concerns while also providing new opportunities for poor people and farmers in developing countries. Can bioenergy fulfill the promise claimed by its proponents? Can it become an environmentally sustainable, economically viable, pro-poor source of energy? And what challenges will meeting these goals present? This set of policy briefs examines the potential opportunities and risks bioenergy may pose for poor people and farmers in developing countries. The briefs consider economic, social, environmental, and science and technology issues. They look at how increased bioenergy production may affect the global food balance and examine the need for further research and development in the bioenergy field. Lessons from the experiences of Europe, as well as Brazil and other developing countries, are reviewed. Recommendations on how to move forward to develop bioenergy in ways that can serve the poor and the environment are presented.