Austrians cast their ballots Sunday in a first round of presidential elections that could advance or block the country's shift to the right.
Social democratic incumbent Heinz Fischer will retire in July after having served 12 years in office.
Former Green party leader Alexander Van der Bellen, far-right Freedom Party legislator Norbert Hofer and the independent former Supreme Court chief Irmgard Griss are top contenders to succeed Fischer.
They have scored between 22 per cent and 25 per cent each in recent surveys.
"My feeling tells me that it's looking good," Hofer said after he cast his vote.
Van der Bellen said he was not sure if he would be one of the two candidates with the most votes and advance to the run-off election in May, even though he has led pre-election surveys. "I humbly await the outcome," he said.
Although it is mostly a ceremonial role, the Austrian president also chooses the chancellor and swears in the cabinet after parliamentary elections.
In light of a possible victory for the opposition Freedom Party (FPOe) in the 2018 parliamentary elections, this year's presidential vote may chart the course of Austrian politics.
The anti-immigration and anti-EU FPOe has enjoyed the support of 30 per cent of voters for nearly a year, coinciding with the surging migration crisis.
The social democrats and the centre-right conservatives that form the current government trail behind the rightists, surveys show.
Van der Bellen promised that he would not appoint an FPOe-led government, as opposed to his right-wing rival Hofer. Griss has said she would respect the election outcome and would appoint such a cabinet.
The government parties' candidates, social democrat Rudolf Hundstorfer and conservative Andreas Khol, stand little chance of advancing into the next round, according to surveys.