Tens of thousands of people took part in a 'March for Choice' rally in Dublin city centre today.
Organisers said they want a repeal of the Eighth Amendment and legislation for free, safe, legal abortions in Ireland.
The March for Choice rally is the first major demonstration since the Government set an indicative timescale of early summer 2018 for a referendum on the section of the state's constitution that ensures tight legal restrictions on terminations.
Meanwhile, the Pro Life Campaign held small rallies in Dublin and at several other locations across the country calling for the retention of the Eighth Amendment.
Organisers of the March for Choice said today's turn-out was the biggest since the marches began five years ago.
The Abortion Rights Campaign, which organised the rally, estimated the turnout to have been 40,000.
The demonstrators gathered at Parnell Square from lunchtime before making their way down O'Connell Street towards Merrion Square.
Speakers then addressed the crowds at Merrion Square.
A pro-choice rally was also staged outside the Irish Embassy in London today, with campaigners highlighting the numbers of Irish women who have travelled to Britain for an abortion in the last three decades.