The concept of sustainable development from 1980 to the present has evolved into definitions of the three pillars of sustainability (social, economic and environmental). The recent economic and financial crisis has helped to newly define economic sustainability. It has brought into focus the economic pillar and cast a question mark over the sustainability of development based on economic progress. This means fully addressing the economic issues on their own merits with no apparent connection to the environmental aspects. Environmental sustainability is correctly defined by focusing on its biogeophysical aspects. This means maintaining or improving the integrity of the Earth's life supporting systems. The concept of sustainable development and its three pillars has evolved from a rather vague and mostly qualitative notion to more precise specifications defined many times over in quantitative terms. Hence the need for a wide array of indicators is very clear. The paper analyses the different approaches and types of indicators developed which are used for the assessment of environmental sustainability. One important aspect here is setting targets and then “measuring” the distance to a target to get the appropriate information on the current state or trend.