The first country to ratify the treaty was Slovakia and the last one to do so was Germany.
The following is a chronology of the ratification process.
1. Slovakia - February 1, 2012 - Parliament ratifies Croatia's EU accession treaty.
2. Hungary - February 13 - Parliament ratifies Croatia's EU accession treaty.
3. Bulgaria - February 17 - Parliament ratifies Croatia's EU accession treaty.
4. Italy - February 28 - The parliamentary ratification process ends with the approval of the treaty by the Senate; the House of Representatives approved it on February 15.
5. Malta - March 5 - Parliament ratifies Croatia's EU accession treaty.
6. Latvia - March 22 - Parliament ratifies Croatia's EU accession treaty.
7. Lithuania - April 26 - Parliament ratifies Croatia's EU accession treaty.
8. Cyprus - May 3 - Parliament ratifies Croatia's EU accession treaty.
9. Czech Republic - June 8 - The treaty ratified by the House of Representatives; Senate did so on April 25.
10. Ireland - June 26 - the parliamentary ratification process ends with the approval of the treaty by the Senate; the House of Representative approved it on June 19.
11. Romania - June 26 - Both chambers of parliament, the House of Representatives and the Senate, ratify Croatia's EU accession treaty.
12. Austria - July 6 - The parliamentary ratification process ends with the approval of the treaty by the Federal Council; the National Council approved it on July 4.
13. Estonia - September 12 - Parliament ratifies Croatia's EU accession treaty.
14. Portugal - September 21 - Parliament ratifies Croatia's EU accession treaty.
15. Poland - October 4 - The parliamentary ratification process ends with the approval of the treaty by the Senate; the Sejm did so on September 14.
16. Luxembourg - October 9 - Parliament ratifies Croatia's EU accession treaty.
17. Spain - October 24 - The parliamentary ratification process ends with the approval of the treaty by the Senate; Congress did so on October 11.
18. Greece - October 30 - Parliament ratifies Croatia's EU accession treaty.
19. Sweden - November 7 - Parliament ratifies Croatia's EU accession treaty.
20. Finland - December 18 - Parliament ratifies Croatia's EU accession treaty.
21. France - January 17, 2013 - The National Assembly ratifies Croatia's EU accession treaty; the Senate approved it on January 15.
22. United Kingdom - January 21 - The parliamentary ratification process ended with the approval of the treaty by the House of Lords on January 21; the House of Commons approved it on November 27, 2012.
23. Slovenia - April 2 - Parliament ratifies Croatia's EU accession treaty.
24. Belgium - April 11 - The parliamentary ratification process ends with the approval of the treaty by the parliament of the French-speaking community.
25. Netherlands - April 16 - The parliamentary ratification process ends with the approval of the treaty by the Senate; the House of Representatives approved it on February 5.
26 - Denmark - May 2 - Parliament ratifies Croatia's EU accession treaty.
27 - Germany - May 16 - The Bundestag ratifies Croatia's EU accession treaty. The formal approval in the Bundesrat is expected during a plenary session which begins on June 7.
The Croatian parliament ratified the EU accession treaty on March 9, 2012.