Slovenia becomes a member of NATO.
Slovenia becomes an EU member state.
The first elections to the European Parliament are held in Slovenia; seven MEPs are elected: Mihael Brejc, Mojca Drčar Murko, Romana Jordan Cizelj, Aurelio Juri, Jelko Kacin, Ljudmila Novak and Alojz Peterle.
At the Oath of Office ceremony at the Court of Justice of the European Communities, European Commissioners from ten new member states are sworn in. Janez Potočnik (Slovenia) is appointed European Commissioner for Science and Research in the (first Barroso) European Commission (2004 - 2010). In 2010, he becomes the European Commissioner for the Environment.
At the 2004 Olympics in Athens, Slovenian athletes win 4 Olympic medals: rowers Iztok Čop and Luka Špik win a silver medal in the men’s double sculls; the track and field athlete Jolanda Čeplak, the world indoor record holder in the women’s 800 metres, wins a bronze medal; Urška Žolnir wins a bronze medal in judo in the under 63kg category; and Vasilij Žbogar, the 2003 European champion, wins a bronze medal in the laser sailing competition.
At the 2004 parliamentary elections in Slovenia, the Slovenian Democratic Party gets 29,08%, Liberal Democracy of Slovenia 22,8%, United list of Social Democrats 10,17%, New Slovenia - Christian People's Party 9,09%, Slovenian People's Party 6,82%, Slovenian National Party 6,27% and Democratic Party of Pensioners of Slovenia 4,04%.
Slovenia, as the presiding country, hosts a two-day Central European Initiative Summit attended by the Prime Ministers of seventeen member states in Portorož.
Janez Janša forms a coalition government, composed of the Slovenian Democratic Party, New Slovenia - Christian People's Party, Slovenian People's Party and Democratic Party of Pensioners of Slovenia