The Health Minister has admitted emergency department waiting times of up to 14 hours for over-75s are unacceptable.
It comes after a parliamentary question to Sinn Féin's David Cullinane revealed people over 75 are waiting on average almost 14 hours for emergency department admission.
The average wait was 28.8 hours in Cork University Hospital and 26.8 in Cork's Mercy Hospital.
Health Minister Stephen Donnelly said the Department of Health is working to alleviate wait times by taking action including enhanced primary care services.
It's too long, it's completely unacceptable.
"It is too long, it's completely unacceptable. I've seen personally, no doubt you have too, the distress in the overcrowded emergency departments, distress to patients, distress to their families, and distress to healthcare professionals right across the country."
Mr Cullinane, Sinn Féin's spokesperson on health, has called on Minister Donnelly to implement a zero tolerance plan to "end long emergency department waits".
The data shows that emergency department wait times are worst in Cork, Limerick, South Dublin, Galway and Kildare where the average emergency department wait time is greater than 20 hours across Cork, Mercy, St Vincent’s, Galway, Naas and Tallaght Hospitals.
Patients have been suffering the torturous consequences of overcrowding for years.
Mr Cullinane said: “Patients have been suffering the torturous consequences of overcrowding for years, but these figures show that the problem has reached a new extreme.
“Older patients across Galway, Limerick, South Dublin, and Kildare are waiting more than 19 hours for admission through an emergency department.
“That is not the extreme end of the scale – that is the average, and it is both shocking and frightening for those patients and anyone looking on.
“The root causes of emergency department dysfunction are low hospital capacity, poor management of resources, delayed discharges, low out-of-hours GP coverage, and a lack of alternatives in the community."
He added: “There is a high degree of burnout across the health workforce, and there is, without question, a need for more beds, doctors, nurses, allied health and social care professionals, and more capacity in diagnostics and operating theatres, but that is not all.
“There are efficiency reforms that have worked in some hospitals, such as Our Lady of Lourdes in Drogheda and in Cavan Hospital, to reduce overcrowding and delays in admitting, seeing, treating, and discharging patients, such as specialist medical wards and better patient flow pathways.
“All hospitals must act on each other’s successes and failures, and it is the Minister’s responsibility to ensure that the HSE is implementing best practice in each and every hospital."