The Educational Institute is calling for all teachers in pre-school services to be qualified and registered by 2020.
The union says only then will children get the maximum benefit from early education.
Currently only 50 percent of staff at a teacher-led centre have to be qualified and registered.
Institute spokesperson Virginia Oakly says teaching children under the age of five is specialised and the more teachers there are, the better the service.
She says the Government should recognise that, with increased funding.
But the Early Childhood Council, representing early childhood education centres, says more qualified teachers at a centre does not necessarily mean it offers a higher quality service than that provided by a centre with fewer qualified teachers.