The State spent just under €2m last year on a scheme that favours the country's wealthier schools, according to data released to RTÉ by the Revenue Commissioners.
Last year, 171 schools availed of a special tax break that allows them to claim money back on voluntary contributions worth €250 or more.
Two schools got an additional €72,500 in State support as a result of the scheme.
The majority of the top 30 schools that availed of the measure were in Dublin.
Under the scheme, schools qualify as charities and so are able to claim tax back on donations they receive.
The bigger the donation, the more the school gets in tax back.
For every €250 donated by a PAYE worker on the top rate of tax, the school gets an additional €174 from the State.
Last year, two schools got more than €72,000 back. A further two schools received just under €70,000.
This means all these schools received donations from parents or other PAYE workers worth around €100,000.
Of the top 30 schools benefitting from the scheme, the majority (21) are in Co Dublin.
Of those Dublin schools, ten are in Dun Laoghaire/Rathdown and one is in Fingal.
The tax break was introduced by Ruairi Quinn when he was Minister for Finance in the 1990s.
This data received by RTÉ relates only to donations from PAYE sources. The Revenue Commissioners were unable to provide figures on contributions to schools from the self-employed.
The commissioners were also unable to name individual schools because confidentiality is assured under legislation.