The Children's Rights Alliance has called on the Government to implement a complete ban on slapping children.
The group said the Government should stick to its commitments under international law and ban corporal punishment, even within the home.
The CRA has said it is unacceptable that physical punishment of children by parents, legal caregivers, childminders and foster parents is currently permitted in certain circumstances under Irish law.
The alliance said the Government has until the end of this month to respond to a formal complaint against Ireland by the Association for the Protection of All Children.
It follows recommendations by the UN Committee on the Rights of the Child that slapping be banned in Ireland.
Speaking on RTÉ's Morning Ireland, CRA Chief Executive Tanya Ward said 22 countries across Europe have banned physical violence against children.
"You find it has a very negative effect on parent-child relationships. It can make a child very defiant," she said.
"It can mean the parent has to use a more extreme form of discipline and it does send a message to children that if you are stressed, that the aggressive forms of behaviour are acceptable. You find that it does contribute to things like domestic violence."
The Department of Children and Youth Affairs said corporal punishment is prohibited in a number of settings under Irish law and it said that any proposal to prohibit the defence of "reasonable chastisement" requires careful consideration.
The department said there is a balance to be found between supporting parents in effective parenting, and the use of criminal law to impose criminal sanctions on parents who do not adhere to best practice in parenting.