Over 3,400 of Clare's primary school students are in classes of at least 30 pupils.
New figures from the INTO show over a quarter of young students here are in so-called super-sized classes, though this number is falling somewhat
While 25.1% of students here are in classes of at least 30 pupils, this has fallen from over 28% last year.
Nonetheless, the Irish National Teachers' Organisation says the potential of school pupils is being compromised by larger classes.
Their newly-released statistics show 61% of pupils are in classes of between 20 and 29 pupils, while only 13% of Clare kids are in classes smaller than this.
The EU average is 21 per class, and the INTO says the average class size in Ireland stands at 25 pupils, and is the highest in the country.
The union wants the matter addressed in the upcoming budget, and estimates the cost of doing this at 15 million euro.
