Environmental management systems (EMS’s) are becoming increasingly important for continued exploration and field development worldwide. The new Intl. Standards Organization (ISO) 14000 EMS series will have a major impact on the competitiveness of the international oil and gas E&P industry, including the whole associated service sector. In clarifying the origins of the comparative strategies, this paper will provide an understanding of existing national EMS’s. This will create an international perspective on the management approach needed to ensure that partnership with ISO 14000 will facilitate environmentally sustainable development.