There has been a 50% increase in the number of injuries suffered by prison officers dealing with non-compliant prisoners.
The number of Restraint Interventions went from 91 cases in 2017 to 137 in 2018.
These are instances where an officer may have received an injury during the course of their duties.
Instances, where an officer is struck/assaulted when dealing with a non-compliant prisoner, are not counted in the restraint intervention figures but recorded in the assault figures.
In total, across the prisons and places of detention, there were 110 assaults staff by prisoners in 2018.
The prison with the highest number of recorded assaults last year was Mounjoy (male) with 24 followed by Cork with 15.
Three prisons or detention centres did not record any incidents of assault: Arbour Hill, Loughan House and Shelton Abbey.
The number of prisoner-on-staff assaults in 2018 were:
Arbour Hill - 0
Castlerea - 12
Cloverhill - 11
Cork - 15
Dóchas Centre - 8
Limerick - 8
Loughan House - 0
Midlands - 13
Mountjoy (male) - 24
St Patrick's Institute - N/A
Portlaoise - 4
Shelton Abbey - 0
Training Unit - N/A
Wheatfield - 5
Prison Service Escort Corp - 9
Operational Support Group - 1
The figures have been released under the Freedom of Information Act.
The Prison Officers Association says overcrowding is contributing to a rise in the number of assaults on staff.
Deputy General Secretary of the POA, Jim Mitchell says he is disappointed rather than surprised by the figures.
"While the gangs and the drugs are an ongoing issue, the re-emergence of overcrowding within the prisons has led to a huge increase in our opinion on assaults," said Mr Mitchell.
In November 2018, the Midlands prison opened a Violence Reduction Unit where prisoners "will benefit from a purposeful regime and are supported to address their challenging behaviour with a clear focus and emphasis on progression and re-integration".
The number of prisoner-on-prisoner assaults rose marginally on the previous year with 418 assaults recorded in 2018 compared to 417 in 2017.
Once again Mountjoy (male) has the highest number of assaults with 110 prisoner-on-prisoner assaults recorded at the prison last year.
It is followed by Castlerea with 76 and Cloverhill with 54 assaults recorded.
The number of prisoner-on-prisoner assaults in 2018 were:
Arbour Hill - 1
Castlerea - 76
Cloverhill - 54
Cork - 42
Dóchas Centre - 28
Limerick - 28
Loughan House - 0
Midlands - 44
Mountjoy (male) - 110
St Patrick's Institute - N/A
Portlaoise - 0
Shelton Abbey - 3
Training Unit - N/A
Wheatfield - 20
Prison Service Escort Corp - 12
