The inability to control the longwall roof and face can result in injury, loss of production, and increased operating costs. Problems such as falls of rock from the roof in front of or above supports as they are advanced and sloughing of coal from the face, along with geologic anomalies such as faults and clay veins, must be controlled before maximum safety and production can be realized from the longwall system. In Europe and the United Kingdom, coal operators have for many years been using a variety of injection and/or doweling techniques and materials for stabilizing their roof and face. In recent years similar technology has been made available to U.S. coal operators through U.S. companies which have been supplying stabilization materials and providing application technology and equipment. The Bureau of Mines, through its in-house and contract research efforts, has reviewed both foreign and domestic longwall stabilization techniques and materials. Although some problems with cost, safety, and application still exist, use of stabilization materials and techniques to address ground control problems on U.S. longwalls has increased dramatically in the last several years.