Nationally, the average rate of classrooms with more than 30 pupils is 11%.
Primary school classes in Laois are the least overcrowded in the country.
The Irish Independent is reporting just 6.5% of students in the county are in a class of more than 30 pupils.
Its latest analysis shows a varied picture in the midlands, with Westmeath among the top of the list in terms of overcrowded rooms, at 14.5%.
The figure in Offaly isn't far behind at 12%.
Over 60,000 students were assigned to classes with 30 or more pupils for this academic year, which equates to a national rate of 11.4%.
Despite a low overcrowded classroom rate, Laois schools are still struggling to meet demand, according to a midlands principal.
Principal of Raheen National School and member of the INTO, Niamh Campion, says schools outside Portlaoise are particularly feeling the pressure:
The INTO has called on the government to take action to lower class sizes by two pupils in the upcoming Budget.
Principal of Carlow Educate Together National School, Simon Lewis says class sizes are on the way down, but more needs to be done: