The HSE spent nearly 7 million euro on private ambulances in the first 8 months of this year.
Letterkenny University Hospital had the biggest bill, at just over €1 million.
The overall figure has increased steadily in recent years, with 4.3 million spent in all of 2014.
Over €2.8 million has been spent throughout the entire Saolta Hospital Group.
Sinn Féin’s health spokesperson, Louise O’Reilly, says it’s a waste of money: