The Immigrant Council of Ireland helped 23 victims of human trafficking last year.
According to its new Impact Report, all were women and 20 were trafficked for the purposes of sexual exploitation.
Of the remaining three victims, two were trafficked for domestic slavery and one for labour-exploitation.
Brian Killoran, the chief executive of the council, says human-trafficking in Ireland is increasing:
"I think what we've seen in Ireland over the last couple of years is a steady rise in the number of detections of trafficking situations.
"It is an area of concern, definitely, and one which we are endeavouring to raise with the Government on a constant basis.
"Today in Ireland, we have yet to convict a person responsible for trafficking somebody into Ireland. That's a huge gap in our response to this international crime."