A HIQA report on the operation and management of the youth detention centre in Oberstown, Co Dublin has concluded that children in the centre were not always safe.
It also found that the children did not all have a care plan and the centre only complied with one of ten assessed standards.
The report is based on an announced inspection of the facility, which provides a detention and remand service to the courts for children aged ten to 17.
The inspection was carried out over three days last October and November.
It found that best practice was not always implemented in managing behaviour and in the medication management of children, with one child not having their medication administered for three days.
It also found children were also occasionally placed in locked rooms for long periods of time and not all children had care plans, and where they did exist the quality of plans varied.
Of the ten standards assessed the service complied with just one, exceeded none and required improvement in six.
Significant risks were identified in three standards areas.
These were in the Care of Young People, Health and Staffing and Management.
The report also found mandatory training had not been provided to all staff but acknowledged management structures had changed and improvements were slowly being made.
Management of the Oberstown centre is required to address all the findings made in the HIQA report and has already put together an action plan.
Minister for Children James Reilly said the issues raised in the report are a matter of concern in terms of ensuring safe and secure custody for all children in detention.
He said they are being addressed by campus management, reporting to the Oberstown Board.
Minister Reilly also noted that there is a significant change programme being undertaken on the campus arising from the implementation of the Programme for Government commitment to end the detention of children in adult prison facilities.
It includes commissioning of new buildings, a staff recruitment programme, new HR procedures, expanded nursing cover and enhanced offending behaviour programmes.