Over 66,000 people waited more than 24 hours in an emergency department last year, before being admitted or discharged.
Almost 7,200 were in University Hospital Limerick, according to freedom of information figures.
The next worst was Tallaght University Hospital in Dublin, at over 6,900.
Almost 22,000 people over the age of 75 waited over 24 hours in an emergency department last year.
It's one in every nine people in this age group who went to an ED in 2022.
Over 196,000 patients over the age of 75 went to a HSE emergency department last year.
The target is for them to be admitted or discharged within six hours - but that was achieved in less than a third of cases.
21,582 over-75s had to wait over 24 hours, according to freedom of information figures.
83 per cent of these were eventually admitted to a ward, with only 17% discharged.
