Only a third of registered voters participated in Saturday's referendum, reflecting a low-key campaign. All political parties and children's charities supported the "yes" side.
Prime Minister Enda Kenny said Sunday the amendment will allow his government to pass laws making it easier for Irish children to be adopted, for courts to remove children from abusive homes and for children to testify in court.
Analysts say the unexpectedly high "no" vote reflects low turnout among "yes" voters, anti-government feeling, and a surprise Supreme Court ruling.
Ireland's highest court found that the government's information booklet on the children's rights amendment was biased and violated referendum law.
(Copyright 2012 by The Associated Press. All Rights Reserved.)