Serbia's presidential election voter turnout was the worst of the past three failed attempts to elect a leader.
Voter turnout was the lowest of the past three elections
The turnout figure of 39% was less than the last election in December, the Republican Election Commission said.
The election before that also failed to attract 50% of the electorate, needed for a valid ballot.
The extremely low turnout has been blamed on an opposition boycott of the vote and general disillusionment with politics in Serbia.
The Nationalist Serbian Radical Party candidate, Tomislav Nikolic, polled the highest, with 46% of the vote.
The pre-election favourite and government candidate, Dragoljub Micunovic, received 35%.
No date has been set for a new election, but it is likely to be after parliamentary elections which will take place at the end of the year.
The outcome of the weekend election was seen as a setback for the ruling pro-Western coalition as it seeks a mandate for reform at December's parliamentary elections.
To make it even harder to achieve the necessary turnout, it is believed half a million potential voters live abroad and could have only cast their ballots if they returned home.