Over 450 children have been waiting longer than two years for speech and language therapy.
According to Freedom of Information figures released to Today FM, there are nearly 11,600 children waiting for their initial speech and language assessment in Ireland.
Of those, nearly 1,300 are waiting longer than a year and 452 are waiting over two years.
Former Irish Medical Organisation President Dr Martin Daly said the figures are unacceptable.
"Children who have needs that need to be addressed early in their lives to improve both their quality of life and also their future development have been left waiting on this where there is no certainty about being seen," he said.
"We are seeing this is general practice and not just in this area but also other allied health professions. It is emblematic of what is happening in the community."
Meanwhile, 5,538 children have been assessed but are still waiting for their first therapy session.
Dr Daly said the delays can have a big impact on a child’s development.
"Firstly, there is the anxiety and the worry it causes parents and then it sets back their development so not only are there issues around their educational development but there are also issues around the possibility of them having physical problems because of their swallowing problems.
"So, there are very considerable risks for children who are left for up to two years."
The area with the longest waiting lists is south Tipperary, Carlow/Kilkenny, Waterford and Wexford.
343 children there have been waiting over two years for their first therapy session in this area.