Over 560 adults who were abused as children have not been allocated a social worker.
They include 70 'high priority' cases.
The second highest total nationally is in Galway and Roscommon.
The term 'retrospective abuse' refers to abuse an adult experienced as a child - but they only came forward in later life.
In the first ten months of last year, Tusla got 2,404 of these referrals.
According to the child and family agency's latest figures, for last October, 565 retrospective abuse victims have not been allocated a social worker.
It's an increase of 16 from September.
The highest number is in Waterford and Wexford, at 88, followed by Galway and Roscommon, at 73.
Tusla says where a case is awaiting a dedicated social worker, it is actively reviewed by the local social work team leader.
And where there is an immediate risk to a child or young person, there is an immediate protective response.