Polls have opened in twin referendums on proposed changes to the Constitution.
The referendums propose changing the wording of the Constitution relating to the areas of family and care.
The family amendment proposes extending the meaning of family beyond one defined by marriage and to include those based on “durable” relationships.
The care amendment proposes deleting references to a woman’s roles and duties in the home, and replacing it with a new article that acknowledges family carers.
The Constitution is the fundamental legal document for the country and can only be changed with the approval of Irish citizens through a national vote.
The campaigns have led to national debates over the role of women in the home, what responsibility the State has for care and the meaning of family.
The Government is campaigning for a yes vote in both amendments. It says the changes will remove sexist language, recognise family care and extend protection to families not based on marriage.
All Irish citizens that are at least 18 years old are eligible if they have registered to vote.
Registered voters are given polling information cards directing them to their nearest polling station.
The family amendment will be on a white-coloured ballot paper while the care amendment will be on a green-coloured ballot paper.
The polls are open between 7am and 10pm.
The result of the referendums, which are decided by majority, are expected on Saturday.
Counting of the ballots happens at a constituency basis at various centres around the country.
However, the overall national result will be declared at Dublin Castle.
The family amendment will be counted and declared first.
The results for the care amendment will not be processed until the family count is finished.