The 22nd Informal Meeting on Mass Spectrometry (IMMS) took place on 2-6 of May 2004 at the Degenfend Palace at Tokaj, Hungary. This small, pretty village is known worldwide for the production of a very good and particular wine, but this was not the main reason for organizing the meeting there! The choice was done in the spirit of IMMS, which favours a relatively small meeting to achieve the maximum level the interchange of information and experience among the participants (as well as to prevent them escaping from the conference!). Significantly, this was the first 'European' science meeting in Hungary, immediately following accession of Hungary into the European Community one day earlier. Joking aside, the meeting was a success, with about 120 active participants from Europe and North America and 44 oral and 70 poster presentations. Monday was devoted to 'Focus on biomedical applications and proteomics', Tuesday to 'Focus on theory' and Wednesday to 'Applications in different fields'. Hence the participants could have a general view of the 'state of the art' of mass spectrometry, but overall could present and discuss, in a relaxed atmosphere, their findings and their thoughts on the technique. This very good result was achieved thanks to the efforts of the local organizers: Károly Vékey, Chairman of the meeting, and all his active and always available co-workers: Mária Bihari, Lászl ó Drahos, Ágnes G öm öry, Timea Imre, J ózsef Jek ö, Kriszina Ludányi,