Twelve old and infirm sisters, aged in the range of 78 to 95, are to be separated after years together and moved to different nursing homes under the plan.
The closure would also bring the loss of 22 jobs in a town that is recognised as among the worst unemployment black spots in Ireland.
Shocked staff have been told that the Trócaire unit, which is attached to the Mercy Convent at Greenhill, is to close its doors by the end of the year.
The 13-bed centre, which is run by the Mercy Order and opened in 2000, employs nine full-time and thirteen part-time staff, including nurses, carers and housekeepers.
The majority have worked at the unit since it opened and most are the sole breadwinners in their families.
Meanwhile, the elderly nuns they care for have a high level of dependency, with nine suffering from varying degrees of dementia.
It is understood that the Mercy Order is closing Trócaire and similar units in Munster for financial reasons, with each bed costing an estimated €53,000 annually.
Staff at the Trócaire unit in Carrick-on-Suir are being offered basic statutory redundancy, together with an unspecified "gift.”
The nuns cared for at the unit are to be transferred gradually as nursing home places become available and the centre is scheduled to close its doors for the last time on December 1.
SIC: CIN