The "Bologna Process", started in 1998/99 with the Sorbonne and Bologna Declarations and now involving 40 countries, aims at establishing by 2010 the "European Higher Education Area", based on "a system of easily readable and comparable degrees". The actual implementation of this process and its relevance for the European labour market requires a convergence also of the accreditation procedures of educational programmes, that are still very different from a European country to the other. After defining the term "accreditation" in the context of the formation of engineers, this paper will discuss the present situation of accreditation of engineering educational programmes in Europe, and present some examples. The contribution of the Thematic Network E4 will be illustrated, and the most recent developments, aiming at a European-wide accreditation system, will be introduced.