Patients were waiting an average of over 11 hours to access emergency departments last month.
HSE figures given to Sinn Féin Health Spokesperson David Cullinane show Mercy University Hospital in Cork had the highest average wait time in the country, at 21.6 hours.
Cork University Hospital was second highest, with average wait times of 19.6 hours.
Patients had to wait an average of 18.4 hours for access to the emergency department in Tallaght University Hospital, and 16.8 hours in St Vincent's University Hospital.
Waiting times were longer for people aged over 75 than under 75.
