The number of people waiting on a trolley at Letterkenny University Hospital during the month of April increased 15% when compared to the same period last year.
There were 594 people without a bed at the hospital over the past month, making it the 5th most overcrowded in the country.
Over 11,070 patients, including 258 children, were admitted to hospital without a bed in April, according to the Irish Nurses and Midwives Organisation.
INMO General Secretary Phil Ní Sheaghdha says, the level of overcrowding in April shows that the HSE has not learned any lessons when it comes to reducing the number of patients on trolleys.
