This article, prepared for the forthcoming second edition of the New Palgrave Dictionary of Economics, provides an overview of the economics of environmental policy. Included are the setting of goals and targets, notably the Kaldor-Hicks criterion, and the related method of assessment known as benefit-cost analysis. Also reviewed are the means of environmental policy, that is, the choice of specific policy instruments, featuring an examination of potential criteria for assessing alternative instruments, with focus on cost-effectiveness. The theoretical foundations and experiential highlights of individual instruments are reviewed, including conventional command-and-control mechanisms and market-based instruments.