What is the current and future role of international environmental law in directing and controlling the conduct of business enterprises, particularly multinational corporations? This book responds to this question by identifying corporate accountability standards and discussing their implementation by international organizations. This is the first book to examine systematically all international sources of corporate accountability standards with specific reference to environmental protection and to elaborate on their theoretical and practical implications for international environmental law. The book argues that although international environmental law does not bind multinational corporations and other business entities, growing international practice points to the emergence of legal standards. These standards allow adapting and translating inter-State obligations embodied in international environmental law into specific normative benchmarks to determine the legitimacy of the conduct of the private sector against internationally recognized values and rules. The role of international organizations that, in the absence of State intervention, identify and promote the application of selected international environmental standards is analysed in depth. This analysis demonstrates how these international organizations are a driving force in establishing and operationalizing international standards for corporate environmental accountability.