Over 600 incidents of violence, harassment and aggression impacting patients have taken place at hospitals serving the Shannonside region in the last three years.
The figures come as part of a report by The Journal Investigates into challenging behaviour at the country's hospitals.
259 have taken place at Sligo University Hospital.
Figures were similarly high at the Midland Regional Hospital in Mullingar at 164.
19 incidents have been reported at Roscommon University Hospital and 183 at Portiuncula.
Author of the report, Noel Baker says health unions argue overcrowding could be a contributing factor: