Protesters marched from Dublin's Parnell Square earlier
The organisers of a pro-life rally in Dublin city say "tens of thousands" of people have taken part.
The campaign had said it was expecting the event to be larger than last year's rally to hear speakers in Merrion Square.
The rally came just days after the Cabinet approved a bill to hold a referendum on the 8th amendment.
The gathering heard from a range of speakers, including doctors.
Speaking ahead of the rally, campaign spokeswoman Niamh Ui Bhriain said: "This will be the biggest event of the campaign, on either side.
"And it will be a direct response from the public to the extreme abortion law to be introduced by Minister (Simon) Harris on Thursday.
"It is becoming clear to the public that a Yes vote is a vote for a copy and paste job of the UK abortion regime - right down to the laughable 'two doctors' provision.
"This is not an abortion law that the Irish public want", she said.
These people took part in the event.
"I was put in a situation 16 years ago, where I was an unmarried mother, and the support and everything that I found in this Ireland - fresh country that we live in now - people helped me", one woman said.
A man said: "Once we start taking away rights, where is it going to stop? Will the right to marry be the next thing, the right to a judge and a jury, the right to vote? What'll be the next thing to come along?"
Another woman added: "I'm here to support life, I believe in the sanctity of life. Choice means kill, and everybody should be aware of that".
"I'm here to support a woman's right to be born - nobody ever thinks about that", another woman said.
A woman from Northern Ireland said: "It's something that we felt very strongly about.
"Although we would have no vote in it... we decided we would join who are usually the silent majority, and come out on the streets and take a stand".
Another woman who is a former midwife said: "Forty years ago I worked in Liverpool and I met a young girl and she was deciding whether to have an abortion or not and I said to her 'Why don't you wait and have the baby and then kill it'.
"And she said: 'Oh my God, that's an awful thing to say' - and I said 'It's the same baby'".
Save the 8th communications director John McGuirk said the result of the upcoming referendum needs to be respected, regardless.
"We're never going to stand in the way of people having a vote - and I think it's very important and we have that vote that there's an honest and a fair debate".
"And that the result - whatever the result may be - is respected by the way, that's very important.
"This referendum is very much there for the winning for us, and we're confident that we're going to win it".