Referendum in theory and practice: the history of the Slovak referendums and their consequences1 Marián Belko, Lubomír Kopeček Abstract: This article deals with the theory and practice of Slovak referendum. Special aim is concentrated on referendum in 1997 (held on NATO accession and on the direct election of the president of the Slovak Republic). Generally speaking referendums brought with a lot of problems. Their outcome was polarization of society and political elite. All Slovak referendums were unsuccessful (with the exception of last referendum – euro referendum in 2003). Concerning the consolidation of Slovak democracy referendums had a negative impact. Key words: Slovakia, referendum, enlargement of the European Union, democracy, parties.