Thirteen children and young people in care, or known to the child protection system, died last year, according to the National Review Panel (NRP).
The panel also found that among the 13 deaths three died by suicide, eight of natural causes, one as a result of an accident and one of unknown causes.
Three were male and 10 were female, 11 were known to social work services while one was in care.
The figure is nine fewer than 2017.
Dr Helen Buckely, Chair of the NRP, said: “On behalf of the NRP I wish to extend my sincere sympathies to families, friends and all those affected by the deaths of the children and young people reviewed by the National Review Panel in 2018.
"The death of a child is an unthinkable tragedy and one which has a profound effect on many.”
Dr Buckley added that out of 12 reviews in 2018, there was "good practice in a number of cases".
She said: "This was particularly evident in the two cases where children died from serious illnesses, where there were examples of consistent child-centered work and excellent interagency cooperation.
"The reviewers found that in some other instances, early responses to referrals that came into social work departments were slow and fragmented, and that some reports were given a less serious classification than was warranted, particularly those where children were at risk from their own behaviour or from the effect of living in adverse circumstances.
"Lack of adequate assessment existed in some instances.
"Service deficits were significant in relation to mental health services and in particular for services for children with autism. In these cases, the burden of responsibility for protecting young people fell disproportionately on Tusla, which has no control over decisions made by health, mental health or disability services.”
