HIQA inspectors have found evidence of poor management and risk to patients at a number of care homes for those with intellectual disabilities.
The organisation published 11 reports this morning.
At one centre housing 40 people with intellectual disabilities in Co Donegal it was found a number of cases of abuse hadn't been reported.
Several allegations of abuse weren't properly investigated.
This resulted in vulnerable residents not being adequately safeguarded and in one instance not believed by staff when they reported an allegation of abuse.
At another unit in Cork there was evidence that one resident hadn't been provided with food for 18 hours.
The HIQA report said a healthcare plan for food and nutrition wasn't being followed at three units on the St Raphael's Campus in Youghal.
Another small centre in Westmeath had four of the inspection results judged as seriously non compliant.