The number of staff in Roscommon Hospital has increased by over a third over the past five years, according to the Department of Health.
There were 459 whole-time equivalent staff in the hospital in January - an increase of almost 38 per cent from December 2019.
All other hospitals that serve the Shannonside region also saw increases of at least 25 per cent, including Sligo, Tullamore, Mullingar and Ballinasloe.
It comes as several unions are threatening industrial action due to "unsafe" staffing levels.
Councillor Valerie Byrne, from the Roscommon Hospital Action Committee, says the hospital still doesn't have enough staff.