Election officials will begin preparations today for the official counting of the votes cast in the European Parliament election.
The ballot boxes will be opened today in the King's Hall in Belfast and the numbers of votes verified before counting starts on Monday morning.
As the polls closed at 10pm last night, politicians feared that turnout might be down on previous European elections.
Anecdotal evidence from around Northern Ireland led to speculation that voter apathy in the wake of the Westminster expenses scandal may have caused voters to stay at home.
The eligible electorate in Northern Ireland is 1,141,979, an increase on the 2004 figure of 1,072,669.
At the last European poll, 51.72% of people eligible to vote did so, which represented 554,744 votes.
Northern Ireland has seven candidates fighting for the region's three European Parliamentary seats.
They are Stephen Agnew of the Green Party, Jim Allister of Traditional Unionist Voice, Bairbre de Brun of Sinn Fein, Diane Dodds of the DUP, Alban Maginness of the SDLP, Jim Nicholson of the Ulster Conservatives and Unionists, and Ian Parsley of the Alliance party.
With three unionist parties splitting the vote of that section of the electorate, Sinn Fein is tipped to top the European poll.
It would be the first time the republican party has emerged from an election in Northern Ireland as the lead party.
Sinn Fein MEP Ms de Brun is tipped to hold on to her seat.
The Democratic Unionist Party's Ms Dodds is fighting to reclaim a seat held by leader of the hardline Traditional Unionist Voice (TUV) Mr Allister.
Mr Allister won a European Parliamentary seat at the last election standing on the DUP ticket, but he left the party after it opted to enter power-sharing government with Sinn Fein.
Ulster Unionist Mr Nicholson is defending his seat on a joint ticket with the Conservative Party.
And while the SDLP challenger Mr Maginness was seen as an outside bet earlier in the campaign, he has claimed he could seize the final seat from Mr Nicholson.