There were 552 patients on trolleys or on wards this morning waiting for admission to a hospital bed, according to the Irish Nurses and Midwives Organisation.
The HSE's figures for patients on trolleys only is 406.
The hospital worst affected today with overcrowding is University Hospital Limerick with 51 patients waiting.
Other hospitals affected include St Vincent's with 37 patients waiting, and Letterkenny General Hospital with 35.
The highest figure recorded was 677 on 3 January.