Polling stations will close at 19.00 hours.
A total of 4,403,871 citizens have the right to vote. Of this number 4,003,645 are in Croatia while some 400,000 reside abroad.
Croatians living abroad will be able to cast their votes in 50 countries at 155 polling stations.
The presidential candidates are Djurdja Adlesic, Miroslav Blazevic, Ljubo Cesic, Mladen Keser, Jadranka Kosor, Doris Kosta, Ante Kovacevic, Slaven Letica, Stjepan Mesic, Boris Miksic, Ivic Pasalic, Tomislav Petrak and Miroslav Rajh.
The candidates need at least 50 percent plus one vote to get elected.
Preliminary results are expected to be released shortly after midnight.