Half the people who contacted the rape crisis centres in the country last year reported that they had been abused as children by a family member.
And almost seven out of ten who suffered sexual abuse solely in their childhood were victims of more than one perpetrator.
The figures were released by the Rape Crisis Network.
The figures are drawn from the work of 13 centres and show that rape and child sexual abuse remain common and endemic in Ireland, according to the RCNI.
Those abused by family members in childhood said the abuse is still affecting their daily lives.
Another one-third of survivors reported having been raped as adults. The family home is the site of sexual violence for many adult women, with almost one third of it being inflicted by a current or ex-partner.
One in six of the people taking up services of centres last year had told no-one else about their experiences of sexual violence, meaning that they had been getting no ongoing support.
Caroline Counihan, Director of Rape Crisis Network Ireland, said the number of survivors using its services reporting to the gardaí had risen significantly to almost four out of ten.
That is twice the reporting rate for those who had experienced sexual violence solely as children.
