The average annual cost of sending a child to secondary school is now around €1,500.
It's up by around €24 since last year, while the cost for primary school children has also gone up by around €60 to more than 1,100.
The figures are part of a study from the Irish League of Credit Unions, with the survey showing 71% of schools are seeking a "voluntary contribution"
School books top the price list of most expensive items for parents, while extracurricular activities were also having an effect on wallets.
Journalist Jen Hogan says it is getting more and more costly to school children.
She said: “It’s hard to believe we’re having this conversation again.
"Every single year we’re having this conversation about the excessive cost of back to school, and nothing ever changes.
“The cost of books, activities children do, stationary, bags, transport… it all adds up."