Voters will go to the polls today to cast their ballots on whether to replace or retain the Eighth Amendment which provides for the equal right to life of the mother and the unborn.
Polling stations around the country open at 7am and will close at 10pm tonight.
After months of political debate and an eight-week long referendum campaign it is now decision time for voters.
Ballots will be cast at more than 6,500 stations across the country.
Voters will decide whether or not to replace or retain the Eighth Amendment although such wording is not mentioned on the ballot paper.
Instead they will be asked whether or not they approve of a bill to delete the Eighth Amendment and insert new wording into the constitution stating that "Provision may be made by law for the regulation of termination of pregnancy".
Those who want to retain the Eighth Amendment will vote no, while those who want to replace it will vote yes.
Voters are being advised to bring their polling card along with identification such as a driver's license or passport. Those without a polling card should bring identification and also proof of address.
Given the strong views expressed by both sides during the campaign there will be much interest in the turnout and whether it will surpass 60%, as was the case for the same-sex marriage referendum.
Meanwhile, the results of an exit poll will be announced on RTÉ's Late Late Show and on the RTÉ News website tonight.
A polling company will interview 3,000 people across the country immediately after they have voted.
The exit poll is being conducted by RTÉ in conjunction with a number of Irish universities, and will be carried out by Behaviour & Attitudes.
The overall Yes/No exit poll outcome will be announced tonight, with further results and demographic breakdowns to be released at 8am on Saturday morning.
Read more:
Referendum: The ballot paper explained
A guide to the referendum
