PRESIDENTIAL ADDRESS There is no doubt that the content of this EAES Consensus Development Conferences (CDCs) booklet represents an extremely important contribution to answering the following questions: which area of endoscopic surgery requires quality assurance ? what methodology should be employed ? what further action is required ? In order to try to answer these questions, the Executive Office of the EAES decided to appoint an "ad hoc" working group which started its activity in 1993. Under the Presidency of Professor Hans Troidl and the scientific mandate of Professor Edmund Neugebauer the Consensus Development Conferences appea­ red as one of the essential educational programmes of the EAES. These were orga­ nized thanks to the scientific and secretarial assistance of the 2nd Department of Surgery, University of Cologne. Besides the appointed chairperson, each Conference was led by a clinical chairman who included surgical experts from various countries of Europe: J. Perissat, W. Wayand, A. Fingerhut, A. Paul, E. Eypasch, C.K. Kum. Of course the EAES Congress Presidents and the panel members should be ack­ nowledged for their important input in the Consensus Conferences. From 1994 to 1998 six themes of endoscopic surgery have been assessed and their recommendation were presented and discussed during the European Congresses held in Madrid, Trondheim, Istanbul and in the World Congress Rome 98.