Tallaght Hospital is promising to carry out an internal review after an elderly patient was left on a trolley for 29 hours.
The consultant who raised the case says the 91-year-old - who has Parkinsons - was left to 'fester' in 'inhumane' conditions.
The man's wife, who is also in her nineties, was also left on a trolley.
A statement for the hospital said "the patient, who suffers from a chronic condition requiring regular attendance at the Hospital, has expressed his appreciation for the standard of treatment received throughout all his periods of care at Tallaght Hospital."
"While the Hospital apologises that the patient in question was subject to an unacceptable delay prior to being transferred to a ward bed on Monday, the Hospital also has a strong duty of care to safeguard the interests of all its patients and will take necessary steps to ensure these are upheld at all times."
Enda Kenny says that he understands the pressure doctors are under but leaving elderly people on trolleys is unacceptable.
Stephen McMahon from the Irish Patients Association says that overcrowding in hospitals is causing deaths and that everyone is entitled to a high standard of care.
The Irish Nurses and Midwives Organisation is to ballot members next week for industrial action due to overcrowding.
