Although many indicator sets have been developed to characterise sustainability, a lack of available methods and operational tools to assess the sustainability of a farm is often reported. The use of specific indicators can be an interesting response if farmers themselves can use them in a process of self-assessment. First, the French IDEA method (Indicateurs de Durabilité des Exploitations Agricoles) of farm sustainability indicators illustrates the scientific approach adopted by authors to translate the concept of farm sustainability into a system of 41 sustainability indicators covering the three dimensions of sustainability. Secondly, some results are presented from different case studies illustrating tests of the IDEA method. Thirdly, the way of building the indicators is discussed on the basis of some results and of feed back from the users As a conclusion, a recent work linking the IDEA method with the national data bases is mentioned.