- In Croatia, people go to the polls to elect the first ever European MPs of the country, anticipating the formal entry of Croatia in the European Union, in July.
- Former Croatian prime minister Ivo Sanader is sentenced to 10 years in prison in a first-degree verdict. He is the highest official in Croatia to be convicted of corruption.
- Croatia's President Ivo Josipovic and Prime minister Jadranka Kosor sign the accession treaty of Croatia to the European Union, to become the 28th member state on July 1, 2013.
- Prosecutors in Croatia issue an arrest warrant for former Prime Minister Ivo Sanader on suspected corruption charges. He is then arrested.
- Croatia resumes membership talks with the European Union after Slovenia lifts its 10-month embargo.