Turnout levels estimated at over 50%
Voters went to the polls in their droves for the landmark referendum on whether or not to introduce gay marriage.
People have until 10pm this evening to cast their vote on whether to allow same-sex marriage, and whether to reduce the minimum age of presidential candidates from 35 to 21 years.
Voter turnout is high with turnout levels comparable to those of a general election.
The figures so far show between 50% and 60% electorate tunout.
Dalkey in South Dublin reached a 51% turn out by 7pm, while in Cork Central and South Central turnout has been between 40% and 50%.
Turnout figures for the Roscommon - South Leitrim area at 8pm showed a steady increase with the Athlone area turnout now at 48.2% while Boyle is at 45% and in the Ballaghaderreen area turnout is currently at 46.6%.
Across the country too, turnout is well ahead of previous referendums.
Twenty-one countries have already extended marriage rights to same-sex couples with Ireland's electorate of 3.2 million people being given the chance to make history as the first in the world to bring in the reform by popular vote.
Locally, at individual polling stations in schools and community centres, presiding officers remarked at unusually large numbers voting from the time doors opened at 7am.
The country has seen a surge in voter registration in recent weeks, 66,000 mostly young people and students, and among the electorate are 400,000 18-25-year-olds, who Yes campaigners believe will be key to a successful passing of the proposal.
In the last 24 hours social media documented many emigrants, mostly from the UK and Europe, returning home to cast their ballots with their influence and trips back flagged on Twitter with #hometovote.
It is only 22 years since Ireland decriminalised homosexuality.
Voters are now being asked one simple, specific question on whether to amend Article 41 of the 1937 Constitution by adding a new clause to a section titled The Family.
It asks voters to support or reject a change to the 78-year-old document which reads: "Marriage may be contracted in accordance with law by two persons without distinction as to their sex."
It does not suggest any change to the definition of the family or remove any outdated references in the section, including those that state a woman's place is at home.
The huge influx of young and first time voters was said to be creating some issues in some polling stations including people arriving with no identification or polling cards.
Questions were also being raised about why Bibles are visible on some desks as voters show their registration slips.
Officials said it was standard practice and a legal requirement in all polling stations on voting days allowing people to swear as to their identity if they have not brought suitable identification.
If voter turnout continues with the same pattern seen in the morning and early afternoon the overall figure is set to be one of the largest at a referendum.
Among those promoting support for gay marriage on Twitter was Taoiseach Enda Kenny, who said: "For gay sons and daughters, brothers and sisters, family and friends,
Yeats said it best: 'Tread softly because you tread on my dreams'."
More than 2,000 islanders eligible to vote headed to polling stations off Donegal, Mayo and Galway yesterday, maintaining a tradition of early offshore polling days for fear that bad weather will disrupt the counts.
Other countries have held referendums on gay marriage, including Croatia, Slovakia and Slovenia where the extension of the right was not passed by the electorate.
The counting of ballots starts in the 43 constituencies at 9am tomorrow, and a picture of how tight the contest has been should emerge by midday.
Opinion polls put the Yes side well in front until a week ago, but concerns have been growing about undecided voters - around a quarter of those polled declined to declare their intentions.
The Yes campaign has been backed by all the main political parties but a small number of backbenchers are to vote No.
Concerns have grown that the more conservative politicians from the Fianna Fail and Fine Gael parties did not sufficiently canvass support, particularly in rural areas, amid fears of a backlash at next year's general election and a sense of complacency that the proposal would be accepted.
In a separate referendum also being held today, voters are being asked their views on proposals to reduce the age limit on who can stand for the presidency from 35 to 21.