At least 440 patients were waiting for beds in Irish hospitals on Monday morning, according to figures from the Irish Nurses and Midwives Organisation (INMO).
The union's daily update on hospital overcrowding said 351 patients were waiting in emergency departments, while 89 were in wards elsewhere in hospitals.
The most overcrowded hospital on Monday, according to the INMO, was University Hospital Limerick (UHL), where 85 patients were waiting for a bed.
University Hospital Galway followed with 53 patients waiting on trolleys, while 48 patients were waiting at St Vincent's Hospital in Dublin.
According to the Health Service Executive's own figures, 325 people were waiting on trolleys across HSE-run hospitals on Monday.
There were 46 patients waiting in UHL, while St Vincent's Hospital in Dublin had 40 patients waiting for a free bed, according to the HSE's daily urgent and emergency care report.
The HSE figures include patients waiting on a hospital trolley or extra bed placed in an inappropriate space in a hospital ward.
The INMO also counts patients placed on corridors or chairs, elsewhere in hospitals, waiting for admission to a bed.
