Gay rights activists display a rainbow flag in Zagreb in May, 2013.Croatians have voted for amendments to the country's constitution that would ban same-sex marriage, rferl.org reports.
Preliminary results from the December 1 referendum, show 66 percent of voters said "Yes" to including an amendment to the constitution that defines marriage as a "union between a woman and a man."
Turnout was 37 percent.
The referendum is the result of a church-backed initiative in mainly Catholic Croatia.
The vote sparked a heated public debate, splitting the country's 4.2 million people.
The government, human rights activists, and prominent public figures spoke out against the referendum, urging people to cast a 'No' vote.
Opponents noted that Croatia now shares its constitutional definition of marriage with Belarus, Poland, Moldova, Bulgaria, Montenegro and Serbia, where intolerance of same-sex unions is widespread.
Prime Minister Zoran Milanovic had called the referendum "sad and pointless", but said the government would pass a bill giving same-sex couples more rights in the coming weeks.