Fewer than one in 10 pupils in schools in Kildare find themselves in classes of 20 or under.
A teachers trade union is calling on the government to reduce classroom sizes to 19 pupils per group.
While primary school class sizes have dropped to their lowest levels in two decades, Kildare has the largest average class size in Ireland, with 24 pupils per class.
This stands in contrast to counties like Longford, where the average class size is just 20.9 pupils.
Fewer than one in 10 pupils in schools in Kildare find themselves in classes of 20 or under.
Ireland’s average primary school class remains above the EU average at 23 students to one teacher.
The INTO says to achieve its target, teachers must be brought home to Ireland.
General Secretary of the union, John Boyle, says reducing class sizes is vital in shaping Ireland's education system: