A charity working with women in the sex trade said it had helped 94 women suspected of being trafficked.
Ruhama said it had supported 301 woman from 43 countries during 2015 and reiterated its call for new vice laws which decriminalise prostitutes and criminalise the buyer.
Chief executive Sarah Benson said: "When we look at prostitution and sex trafficking it is critical that we become more alert to the gendered dimension of migration and the risks to women and girls.
"So many women and girls already face exploitation and abuse while in transit, therefore it is truly devastating to know that many reach what they believe to be a safe harbour only to find themselves thrust into brothels to be sold for sex."
Ruhama said 66 women were helped through its street outreach service and it dealt with another 12,140 phone calls, 8,146 text contacts and 1,281 direct face-to-face case work meetings with women in the sex trade during 2015.
Ms Benson said a particular concern was the lack of safe accommodation or welfare support for women exiting the sex trade.
"The terrible irony we experience is that we are facing such challenges to get appropriate housing for the women we help, while at the same time most of the victims of trafficking we support were being kept by organised crime gangs in houses used as brothels in ghost estates, urban apartments and other rented accommodations right across the country," she said.
"It is critical that the public are vigilant to the exploitation that is occurring right on our doorsteps. In some cases women have simply fled into the streets to get away from their abusers."
Ruhama called on Ireland to follow Sweden and France and criminalise the buying of sex rather than the prostitutes themselves.
Its annual report also showed 50 women received specialised housing and welfare support.