The One in Four organisation has reported a marked increase in the number of young sex offenders attending it for treatment.
The charity said many of the young men concerned began offending as adolescents by downloading internet images of children being abused and then moved on to sexually harming children themselves.
One in Four professionally supports survivors of sexual violence, and aims to curb abuse.
Last year, for example, it treated 30 sex offenders, working closely with the civil authorities.
In a commentary on its Annual Report for 2013, Executive Director Maeve Lewis said that last year the number of men aged between 18 and 25 referred to it increased to seven, almost a quarter of those treated.
She also warned that the numbers are still increasing.
She said many of them began offending as adolescents by downloading internet images of child abuse and then moved on to sexually harming children themselves.
Ms Lewis said this poses serious questions for Ireland’s digital age society in how young people are supported to develop healthy notions of sex based on consensual sexual intimacy.
Most of One in Four's clients attending for psychotherapy last year had been abused in their own families and neighbourhoods with 17% saying they had been abused by members of the clergy.
Ms Lewis said this reflects more accurately the reality of child sexual abuse in Ireland.
Speaking on RTÉ's Morning Ireland, Ms Lewis said 114 offenders have been treated over the past six years.
She said she was aware that of the majority of men the charity has remained in contact with, four have re-offended.
Minister of State at the Department of Justice Kathleen Lynch has said the Government must work with One in Four to ensure that people outside Dublin can access its services more readily.
She was commenting on a call by the charity for the expansion to every county of treatment services.