| 1 January 2004 | Ireland took over the EU Presidency. |
| 9 January 2004 | The 13th protocol of the European Human Rights Convention abolishing the death penalty was signed by Turkey in Strasbourg. |
| 9 February 2004 | Turkey-Greece Cross-Border Cooperation Programme under Interreg III/A. was affirmed. |
| 19 February 2004 | The negotiations within the framework of Annan Plan started in the island of Cyprus. |
| 22 March 2004 | Republic of Macedonia applied for EU membership. |
| 25 March 2004 | Declaration on Combating Terrorism was adopted at the Brussels Summit. (25-26 MArch) |
| 31 March 2004 | The strategic framework of the Turkey-Bulgaria Cross-Border Cooperation Programme was completed. |
| 1 April 2004 | Parliamentarian Arie Oostlander's "Turkey Report" was accepted in the European Parliament. |
| 6 April 2004 | The 52nd meeting of the EU-Turkey Joint Parliamentary Commission took place in Izmir. (6-7 April) |
| 15 April 2004 | The Memorandum of Understanding on Turkey's participation to the EU Education and Youth Programme was signed between Turkey and the European Commission. |
| 24 April 2004 | The referendum on Annan Plan was held in Cyprus. As a result of the referendum 69.4% of the voters in Turkish Republic of Northern Cyprus accepted the Plan whereas 75.83 % the voters in Greek Administration of Southern Cyprus refused. |
| 29 April 2004 | The Council of the European Union approved the Green Line Regulation. The Regulation deals with the movement of persons and goods across the line. |
| 1 May 2004 | The EU finalized its fifth enlargement with the accession of 10 new member states (Poland, Hungary, Czech Republic, Slovakia, Slovenia, Lithuania, Latvia, Estonia, Malta and the Greek Administration of the Southern Cyprus) to the Union. |
| 6 May 2004 | The 15th meeting of the EU-Turkey Customs Union Joint Committee took place. |
| 7 May 2004 | The Constitutional Reform Package was accepted in the Turkish Parliament. |
| 18 May 2004 | The 43rd meeting of the EU-Turkey Association Council took place in Brussels. |
| 10 June 2004 | The European Parliament elections. (10-13 June) |
| 17 June 2004 | The European Council in Brussels accepted the the Treaty establishing a Constitution for Europe. (17-18 June) |
| 1 July 2004 | The Netherlands took over the Presidency of the Council of the European Union. |
| 7 July 2004 | The European Commission proposed a package of aid and trade measures to encourage the economic development of the Turkish Cypriot community. |
| 21 July 2004 | The fourth meeting of the Euromed took place in Istanbul. (21-22 July) |
| 12 August 2004 | The European Commission declared the new Commission's members and their duties. |
| 5 September 2004 | Enlargement Commissioner Günter Verheugen visited Turkey. 85-9 September) |
| 6 September 2004 | Established in March 2004, the Independent Commission on Turkey published a report called "Turkey in Europe: More than a Promise" |
| 6 October 2004 | The European Commission published the 2004 Progress Report and the Recommendation Document following the Progress Report. Within the framework of this document, Turkey was said to have fulfilled the political criteria in required measure and was recommended to begin to the negotiations. |
| 19 October 2004 | The Greens in the European Parliament organized their annual meeting called "Turkey and the EU: A common future" in Istanbul. (19-22 October) |
| 29 October 2004 | The Treaty establishing a Constitution for Europe was signed in Rome. |
| 4 November 2004 | The European Council took place in Brussels.(4-5 November) |
| 22 November 2004 | The new European Commission took office. |
| 24 November 2004 | The Troika meeting between European Union-Turkey took place in Hague. |
| 29 November 2004 | The meeting of the Europe-Mediterranean Cooperation "EUROMED" Ministers of Foreign Affairs, with the participation of 25 the EU member states and 10 non-member states including Turkey took place in Hague. (29-30 November) The 18th meeting of Turkey-EU Joint Consultative Committee took place in Hague. (29-30 November) |
| 30 November 2004 | Prepared in compliance with the European Commission's Turkey 2004 Progress report and its suggestions, the European Parliament Draft Report on Turkey was accepted by the European Parliament Committee of Foreign Affairs. |
| 1 December 2004 | The Pre-Accession Economic Program of Turkey was presented to the European Commission. |
| 2 December 2004 | The NATO Peace Mission, which had been in Bosnia Herzegovina since 1996, was handed over the EU. The 18th meeting of Turkey-EU Joint Consultative Committee took place in Hague. (2-5 December) |
| 16 December 2004 | The European Council took place in Brussels. The Council decided to open negotiations with Turkey on 3 October 2005.It therefore invited the Commission to present to the Council a proposal for a framework for negotiations with Turkey. (16-17 December ) |