Nursing staff at Saint Ita's Hospital in Portrane in north Dublin are to ballot over the next two days for industrial action, up to and including a strike.
The Psychiatric Nurses' Association said the move is in protest at the growing impact of staff shortages at the Saint Joseph's Centre for Intellectual Disability within the hospital.
The association has 440 members at St Ita's and said staff shortages are having a huge impact on the health, safety and welfare of both service users and staff.
Speaking on RTÉ’s Morning Ireland, PNA representative for St Ita’s Liam Hamill said there was a Labour Relations Commission agreement in 2013 to increase the nursing complement up to 274 staff but it is currently running at 240.
Mr Hamill said this was a having a detrimental effect on staff and service users at the St Joseph's Centre.
He said industrial action would include not answering phones and not driving mini-buses.
The result of the ballot will be known by Friday.
