Teachers' pay, class sizes, funding and school patronage are among the issues being discussed at the INTO annual congress, which gets under way today.
850 delegates will represent 32,000 primary school teachers in the Republic and 6,000 in the North at the conference in Kilkenny.
"Primary class sizes in small schools of less then five teachers have been unfairly increased," said INTO spokesman Peter Mullan, on the issues the congress will address.
"State funding has been cut to all schools, and most of all there's been a failure to resource primary schools for the 21st century - for example with up-to-date broadband or computers and tablets.
"Teachers' pay was reduced again in the last year, [and] extra responsibilities have been imposed."
Secondary teachers unions will also hold their annual conferences this week.