Tusla had more than 82,500 referrals of child protection or welfare concerns last year, according to its annual report.
The child and family agency says that's a 13% rise on the previous year.
At the end of the year about 22,000 cases were open, but 28% of those cases had yet to be allocated a designated social worker.
Tusla says it prioritised cases where children required an immediate response.
Barnardo's CEO Suzanne Connolly says one of its greatest challenges is the recruitment and retention of social workers.
"Tusla has a significant demand for its services, so it needs to deliver on its plan to ensure that it remains a very attractive employer for social workers, in order for it to make its key commitments in relation to vulnerable children."
