Codes of environmental management practice emerged as a tool of environmental policy in the late 1980s. Industry and other groups have developed codes for two purposes: to change the environmental behavior of participating firms and to increase public confidence in industry＇s commitment to environmental protection. This review examines five codes of environmental management practice: Responsible Care, the International Chamber of Commerce＇s Business Charter for Sustainable Development, ISO 14000, the CERES Principles, and The Natural Step. The first three codes have been drafted and promoted primarily by industry; the others have been developed by non-industry groups. These codes have spurred participating firms to introduce new practices, including the institution of environmental management systems, public environmental reporting, and community advisory panels. The extent to which codes are introducing a process of cultural change is considered in terms of four dimensions: new consciousness, norms, organization, and tools.