Ambulances took over an hour to arrive at high priority calls 500 times in the first half of the year.
Between January and June, delays of up to four hours were reported in some high risk cases that the National Ambulance Service had been tasked to.
Cork had the highest number of these instances, with 77 ambulances taking over an hour to arrive, followed by Wexford, Tipperary and Kilkenny.
The Irish Examiner reports that for the most serious calls, 19 minutes is the target response time set out by NAS.
