New figures show that almost 8,900 children were classified as overdue for assessment of need, under the Disability Act, by the end of last year.
Nearly 7,000 children had been waiting for more than three months.
The figures were provided by the HSE to the Sinn Féin's health spokesperson David Cullinane.
An assessment of need identifies whether a person has a disability, any health and education needs arising from that disability, as well as what services are required to meet those needs.
Progress was being made in reducing the waiting list from 6,058 in the third quarter of 2020, down to 1,718 in the first quarter of 2022.
However in March 2022, the High Court found that the HSE's preliminary assessment approach did not meet the requirements of the Disability Act.
This judgement, according to the HSE, resulted in a growth in overdue assessments of need which now stand at a record 8,893 - with 6,963 children waiting for more than three months.
The HSE says that €11 million has been allocated to address waiting lists. It says it is also getting some private assessments for children, but adds such outsourcing is "challenging".
However, Mr Cullinane contends that the High Court ruling had correctly identified that the Government had been trying to short-cut the assessment process and therefore it's responsible for the now record waiting lists.
The TD for Waterford said what's now required is increasing capacity in the Children's Disability Network Teams and making greater use of private sector capacity while, at the same time, building up public capacity.
Minister of State Anne Rabbitte has said that there are "no excuses" for how long the assessment of need waiting lists have gotten.
However she contended: "The High Court decision in 2022 to overturn the use of the HSE's Standard Operating Procedure has seen thousands of children needing to be reassessed, which means the list has grown longer than it otherwise would have.
"The HSE outlined a plan to tackle the AoN waiting list in the PDS Roadmap published late last year, and I secured €11 million in funding specifically for AoNs, as well as another €5 million this year to support the plan," the minister said.
"This will be used on a number of fronts, such as over time and the use of capacity in the private sector. It's important to note that this is in addition to the largest ever recruitment drive specific to the Children's Disability Network Teams that is ongoing at the moment.
"I greatly reduced the overdue AoN waiting list over the course of 2020 and 2021 and I'm confident it can be done again.
"One of my priorities for 2024 is to ensure the HSE delivers and does so within their statutory timelines.
"I'm meeting the nine regional disability managers every month to ensure they are doing what they should be to support the children and families currently left waiting."
