There are 345 patients on trolleys in hospital emergency departments, according to figures from the Irish Nurses and Midwives Organisation.
The worst-affected hospital is the Mid Western Regional in Limerick, with 42 patients waiting.
Other hospitals with a large number of patients on trolleys include Beaumont Hospital with 34 patients and St Vincent's University Hospital in Dublin with 31 patients waiting.
The surge in demand for hospital beds at Limerick's acute hospital is as a result of an increase in the spread of the norovirus, or winter vomiting bug, respiratory illnesses, and other complaints.
There is a complete ban on visiting at the hospital and members of the public are being asked not to go to the hospital's emergency department unless it is absolutely necessary.
Only parents of sick children will be allowed access to the Childrens Ark section of the hospital, and other children should be kept away, hospital authorities have urged.