The Sustainable Development Indicators (SDI) are a tool for monitoring the National Strategy for Sustainable Development (ENDS 2005-2015 / Council of Ministers Resolution No. 109/2007). These indicators (80) are intended to evaluate the progress of Portugal concerning sustainable development in terms of the objectives and targets set in the strategy. They are classified into seven strategic objectives and ranked on three levels. The indicators’ framework is a contract signed with Eurostat to develop a set of indicators to monitor the National Strategy for Sustainable Development.