Dublin's Beaumont Hospital is imposing a total ban on all visiting this weekend to prevent the spread of the winter vomiting bug, Norovirus.
A statement from the hospital said the decision was taken against a backdrop of an increased incidence of the bug in the community.
The hospital said exemptions will only be granted in exceptional circumstances.
The public will also not be allowed to visit patients at St Joseph's Hospital, Raheny.
Beaumont is urging all members of the public who have symptoms of the Norovirus to seek medical advice from their GP before presenting to the hospital's emergency department.
Symptoms of the bug include nausea, vomiting and diarrhoea.
