More than 64,000 ambulances spent over an hour at a hospital last year, before offloading a patient and getting back on the road.
That is nearly one in every four ambulances that arrived at hospitals.
According to freedom of information figures obtained by Newstalk, the 'turn-around time' was over five hours in 165 cases.
David Hall, chief executive of Lifeline Ambulance Service, says the delays are caused by congestion at emergency departments.
"The emergency departments have been neglected by the health service and the HSE. Their staff are overworked and underpaid and there is immense pressure and stress."
He said there are a lot of people who are presenting themselves to A&E, and hospitals are being overloaded.
Mr Hall said ambulances being tied up is "inhumane" and it is putting patents at risk. He said there are a number of ambulances that need to be replaced as well.
Turnaround times involve the interval between an ambulance's arrival at a hospital to when the crew has handed over a patient and is ready to take another call.
The target time is less than 30 minutes.But on 64,182 occasions last year, the turnaround time was over an hour.
That is close to nearly 23 per cent of all ambulances that went to hospitals throughout the country last year.
In 165 cases, the turnaround time was over five hours.
Over 20,000 fewer ambulances had turnaround times of over an hour in 2019 and 2020 as last year.
The HSE says during the Covid pandemic, the National Ambulance Service experienced longer offload delays at emergency departments - due to infection prevention and control measures.
