There were 583 patients on trolleys in emergency departments or wards waiting for admission to a hospital bed this morning, according to figures from the Irish Nurses and Midwives Organisation.
The worst affected hospital was Cork University Hospital with 61 patients on trolleys.
Letterkenny University Hospital and University Hospital Limerick both had 43 patients waiting for a bed.
There were 398 people on trolleys in emergency departments and 185 on hospital wards.
The Health Service Executive's 'TrolleyGar' figures put the number waiting in emergency departments at 430.
The HSE figures only cover emergency departments. Yesterday, there were 541 patients on trolleys, according to the INMO.
Further strike days are scheduled for 5, 7, 12, 13 and 14 February if the dispute is not resolved.