Over 540 people are on trolleys at hospitals across the country, according to the Irish Nurses and Midwives Organisation.
University hospitals in Cork and Galway are the worst affected - with 48 people waiting for admission to beds.
The INMO says the situation has disimproved since December 2015.
On this day last year, there were 331 people on trolleys.
The organisation is calling on the HSE to introduce an emergency nurse staffing initiative to address the matter.