Forage crops are an important potential renewable fuel resource.  Perennial forages can produce large yields of renewable feedstock biomass, require relatively low nutrient inputs compared to row crops, and generate accessory benefits such as erosion stabilization, carbon sequestration, soil remediation, and wildlife habitat, among others. Forages are versatile biofuels that can provide energy through co-firing with coal, direct burning as pellets, and generation of ethanol.  In Europe, the biofuel potential of Miscanthus and reed canarygrass (Phalaris arundinacea L.) has received most of the research effort.  In the USA, the focus has been on switchgrass (Panicum virgatum L.) and alfalfa (Medicago sativa L.).  Each of these forage crops presents a different combination of strengths and weaknesses for biofuel production. Agronomic problems common to many potential biofuel forages include undependable establishment of warm-season grasses, poor stand persistence, and a need for new varieties that are bred specifically for traits valuable in a biofuel feedstock.   Development of such new varieties has been slow because the relative importance of various plant composition traits for energy conversion is incompletely understood.  The value of various traits also depends in part on the energy conversion system being used. Production of feedstocks with the desired composition may require adjustments in forage management practices and will be especially challenging when forage stands are being managed for both energy and conventional uses.