The protest was organised by the Families Unite for Services and Support group and is the third such action since the start of the summer.
The group say long waiting lists, a lack of funding and a recruitment and retention crisis in the public disability service is making their children's lives harder, while forcing them to try to raise the money to access private assessments and therapies.
It has also criticised the Taoiseach for failing to meet with them.
In a response to RedFM News, the Taoiseach's office says Micheál Martin has regularly engaged with representatives of the organisation and says a meeting will be arranged when possible.
RedFM News was at today's protest and heard the words of one HSE disability services employee being read out by one of the protest organisers:
"More often than I want to admit, I sit with parents while they break down before my eyes. I'm there for the tears, the sadness, the anxiety, the anger, the frustration, and the fear. They tell me that they can see their child regressing before their very eyes and feel totally powerless to do anything about it. These people are some of the strongest loving, dignified and motivate motivated people I have ever met. We need to join together as parents, families, friends, professionals and communities to demand better for our children, for their future, for our future."
Families have gathered on Grand Parade in the city to call for more to be done to help them access children’s disability services including assessments and therapies. More on air and online. pic.twitter.com/Xv6F0KSjLU
— RedFM News (@RedFMNews) August 20, 2022
