Biofuels are widely seen as a feasible alternative to oil. Indeed, in 1995 the Clinton Administration proposed amendments to the Clean Air Act that would require gasoline sold in the nine most polluted US cities to contain additives from renewable sources, such as grain alcohol. This move, even if blocked by a three-judge panel of the US Court of Appeals in Washington, DC, has helped to focus attention on the question of whether research and development in biofuel production from agricultural crops should be increased. In Europe, similar fiscal and regulatory provisions have already been introduced. These policies assume that biofuels have the potential to reduce current dependence of industrialized societies on rapidly disappearing fossil energy stocks and that biofuels are desirable from an ecological point of view. But are these assumptions correct? Although abundant scientific literature is available on various biofuel production techniques, attempts to provide a comprehensive evaluation of large-scale biofuel production as an alternative to fossil energy depletion are few and controversial. The complexity of the assessments involved and ideological biases in the research of both opponents and proponents of biofuel production make it difficult to weigh the contrasting information found in the literature. Moreover, the validity of extrapolating results obtained at the level of the individual biofuel plant or farm to entire societies or ecosystems has rarely been explicitly addressed in the literature. In this article, we attempt to provide such a comprehensive assessment of the feasibility of large-scale biofuel production by critically reviewing the existing biofuel literature from a broad perspective.