Almost two thirds of parents say books are the biggest back-to-school financial burden.
A quarter say the back-to-school allowance helps to deal with the pressure but almost one in five resort to taking out a loan.
A third of parents admit to saving throughout the year to cover back-to-school costs.
Justin Healy, Managing Director of Spark Market Research, says book prices continue to be an issue for parents.
He said: "The area that is the most concern for people is schoolbooks and I know we have the ongoing debate.
"People talk about 'should we have schoolbooks?' or 'what should the kids have in their schoolbags?'.
"But we have 60% of people saying that schoolbooks are their biggest expense."
He also said many parents are really struggling financially.
Mr Healy said: "About one in three are saving throughout the year or also dipping into their savings. For some people that's not enough or they just don’t have the savings.
"We actually found that about 20% have to take out a loan, be that from the bank or the credit union, just to make ends meet so they can actually get the back-to-school shopping done."