The Department of Energy's (DOE) Federal Relighting Initiative (FRI), under the Federal Energy Management Program (FEMP), has developed a comprehensive process to assist federal agencies in meeting the nation's energy mandate. This mandate states that federal facilities must use 20% less energy by the year 2000, based on 1985 consumption levels. Because lighting accounts for about 40% of total federal electricity consumption, the FRI was conceived to help reduce energy use in this important area while improving lighting quality and increasing productivity through relighting. Selected federal rules and regulations provide guidance on the types of energy efficiency techniques required, life-cycle costing methods and lighting levels that should be employed to achieve the federal mandate. Although the central focus of this paper is on the environment, this paper takes the perspective that the energy efficiency gains achieved through the FRI would produce both environmental and economic benefits for the United States. For example, improvements in energy efficiency would reduce electricity demand, and would consequently reduce the emissions associated with fossil fuel combustion for power production. These reduced emissions include carbon dioxide, which is associated with the potential for global climate change, and heavy metals, which pose a potential health threat to humans and aquatic ecosystems. Economic benefits of the FRI would include reduced federal expenditures on energy or, possibly, avoiding new power plant construction.This paper begins with a brief overview of the FRI process. Next, current lighting energy use in federal buildings is evaluated and the potential future energy savings achievable through full implementation of the FRI are estimated. The paper then translates these energy savings into avoided emissions of carbon dioxide and heavy metals and into avoided fuel expenditures