The Health Service Executive spent €11.2 million on consultancy fees for the National Children's Hospital last year.
The Dáil's Public Accounts Committee also heard that the National Children's Hospital Group paid almost €1m to Q4 Communications for Public Relations services in the past four years.
This includes €204,000 in 2015; € 274,000 in 2016; €276,000 in 2017 and €248,000 in 2018.
Galway West TD Catherine Connolly, said it's "unacceptable" that this much money was spent on PR.
"I don't think it's good value for money. The story of a children's hospital is a story that is sufficient in itself, why you would need to sell it I don't know," she told the committee.
Committee Chairman Sean Fleming, said it is an issue that will "raise its head again."
He said: "It's something we will be coming back to because the children's hospital won't be going away."
Mr Fleming said the committee would also be seeking more information from the HSE on its spending on consultancy fees in relation to the hospital, which amounted to €11.2m last year.
This included €3.6m on consultancy relating to an ICT digital hospital project; €3.5m in relation to clinical and operational support; €1.8m on design and transitioning; €1.8m on corporate services and workforce change management and €400,000 on project management consultancy.
Correspondence to the committee also revealed that the HSE spent €17.5m on legal services last year.
This includes €9m on solicitors; €3.37m on barristers and €3m on reimbursement of third party legal costs.