It has taken an ambulance at least an hour to arrive at a life-threatening emergency more than 120 times this year.
On one occasion, it was nearly four hours before a patient was attended to.
According to guidelines from the Health Information and Quality Authority, an ambulance should arrive at life-threatening emergencies in less than 19 minutes in 80 percent of cases.
But new figures, released under the Freedom of Information Act, show this target isn't being met in the vast majority of cases.
On 123 occasions in the first nine months of this year, it was more than an hour before an ambulance arrive.
Of the response times of more than an hour, 26 were in Wexford, followed by 20 in Cork and 13 in Kerry.
Nine times this year, it took at least an hour for an ambulance to arrive at a life-threatening emergency in Mayo - one of which was 3 hours and 50 minutes, which was the worst in the country.