There were more than 560 people on trolleys in hospital emergency departments or on wards awaiting admission to a bed on Tuesday morning.
The Irish Nurses and Midwives Organisation (INMO) said there were 412 patients on trolleys in emergency departments and a further 150 on wards.
Among the hospitals worst affected were Cork University Hospital where there were 54 patients waiting for beds, and University Hospital Limerick where there were 49 patients waiting.
There were 47 waiting at St Luke’s Hospital in Kilkenny, according to the INMO figures, and 40 at University Hospital Galway.
Dublin’s Mater and Beaumont Hospitals each had 25 patients waiting for beds.
Last week the Minister for Health Simon Harris forecast that there would be a surge in patients this winter at emergency departments.
Mr Harris said dealing with the overcrowding pressures would require “huge operational grip” and that managers and doctors would have to do all that they could to assist.
He also said that the public also needed to accept this was a very busy time of year.
He added that so far this winter, there had been about 2,000 fewer patients on trolleys compared with this time last winter.
The number of patients on trolleys in emergency departments and on wards generally spikes at this of the year.
In 2011 the then Minister for Health James Reilly pledged that there would never again be 567 patients on trolleys on a single day.
In 2006, as Minister for Health, Mary Harney declared a national emergency when the number hit 495.
However the number of patients on trolleys hit a record 612 in January this year while there were also over 600 waiting for admission to a bed for a period in early 2015.
