Anecdotal evidence suggests some schools actively discourage poorer pupils and Travellers from enrolling, a leading educationalist has said.
Dr Anne Louise Gilligan, of St Patrick's College, Drumcondra, Dublin, said the practice needed to be stopped so that all schools were open to all pupils.
"While it is not formally documented, it is anecdotally known that some schools actively try to discourage the enrolment of Traveller children or they try to ensure that pupils from lower social classes are not enrolled," she said.
Dr Gilligan is director of St Patrick's Educational Disadvantage Centre which studies and draws up policies on the issue of educational inequality.
She was speaking after a week-long conference on the subject organised by St Patrick's which was attended by hundreds of teachers, principals and education experts.
Dr Gilligan said it was time for the introduction of a standardised inclusive enrolment policy for all schools.
This would help to stamp out any possibility of "discretionary decisions" over whether children were allowed to enrol.
Delegates at the conference also recommended a standardised policy of integration in schools and said the teaching staff in the school "should reflect the diversity which was already occurring in Irish classrooms".
While many of the Department of Education's programmes which were designed to tackle disadvantage were commendable, she said, there were "just too many" and they were often disjointed.
"What we need to do now is take stock of what we have learned and put that into everyday practice as part of a systematic overhaul," Dr Gilligan added.
In a draft action plan, developed during the week of workshops and discussion groups, delegates also said it was unrealistic to expect teachers to become "all things to all children".
Teachers alone could not be expected to have all the skills or knowledge required to deal adequately with children with disabilities and children from different ethnic backgrounds, it said.
Also, it was unrealistic to expect that all schools would have all the resources and supports necessary to deal with children's diverse issues and needs, the plan added.