Tallaght University Hospital is urging people with non-urgent needs not to attend its emergency department.
In a statement, the hospital said its ED is under significant pressure due to a high number of patients presenting there.
It has asked the public that, where possible, they should attend their GP, GP out-of-hours service, a local injury unit or local pharmacist, for non-emergency conditions.
However, anyone who needs emergency hospital care should come to the ED, where they will be seen.
TUH said that patients who are presenting to the ED with non-urgent conditions are experiencing very long wait times to be seen.
The Irish Nurses and Midwives Organisation said there were 50 admitted patients at TUH waiting for a hospital bed this morning.
According to its TrolleyWatch figures, the INMO said there were 487 admitted patients waiting for a bed this morning at hospitals around the country.
The hospital worst affected was University Hospital Limerick with 69 patients waiting, with 47 waiting at University College Cork.
