It took an ambulance over an hour to arrive at a life-threatening emergency 63 times in the space of three months.
According to freedom of information figures, the longest response time was almost two hours.
An ambulance is supposed to arrive at a life-threatening emergency in less than 19 minutes.
The longest was 1 hour and 51 minutes to a critical call in Louth, followed by nearly 1 hour and 43 minutes to an emergency in Tipperary, and almost 1 hour and 39 minutes to a case in Galway.
The National Ambulance Service says the average time for delta calls during this period was 17 minutes and 40 seconds.