The official vote tally for Friday's vote has not been finished but exit polls predict a massive victory for repealing the constitutional ban.
Dublin voter Helen, 47, who did not want to give her surname and is now unemployed after suffering cancer, said her radiation treatment would have been stopped had she been pregnant, under existing laws giving equal right to life to expectant mothers and unborn babies.
Residents of Irish islands cast their votes on Thursday local time, to ensure their votes reached count centres on time.
The contested amendment requires authorities to equally protect the right to life of a mother and that of a fetus, from the moment of conception.
Some "Yes" politicians were already calling on the government to pass the legislation without delay following the publication of the exit polls.
These proposed changes, the archbishop concluded, have united all Christian traditions [around the "No" campaign]. "Because it terminates human life which begins at conception, abortion can never be condoned in any circumstances", priests in the Diocese of Achonry wrote in an open letter published by the Irish Catholic Bishops' Conference last week.
GETTY REFERENDUM Ballot papers are handled as officials count votes in the Irish referendum
With that in mind, members of the queer community have travelled from far and wide in the hope that no Irish woman will have to make a journey overseas to terminate a pregnancy ever again.
Ireland appears poised to overwhelmingly overturn a constitutional amendment that bans abortion in nearly all circumstances, according to a exit poll.
"It's an Ireland that is more tolerant, more inclusive and where he can be whatever he wants without fear of recrimination", he said. The only age group that didn't vote pro-abortion by a "whopping majority" was people over 65.
Exit polls indicate that the highest Yes vote was in Dublin, with 77 percent.
Currently, abortion is only allowed when a woman's life is at risk, but not in cases of rape, incest or fatal foetal abnormality. Voters will decide whether or not to abolish the 8th amendment which makes abortions illegal, except when the mother's life is at risk.
Senator Catherine Noone, chairwoman of an Oireachtas committee which recommended the abortion law changes, tweeted: "I'm feeling very emotional tonight - we are a great, compassionate people". "Whether you agree or disagree, it shouldn't be the government or anyone else making that decision".
When voted on, the referendum passed with 66.9 percent voting "yes", and 33.1 percent voting "no". Numerous anti-abortion signs showed photographs of fetuses.