Thousands of people in the northwest are either homeless or live in unsafe or inadequate accommodation, according to the Simon Community.
More than 5,000 people in Sligo, Leitrim and Donegal had some housing need in 2004, the latest year for which official figures are available. Local authority and voluntary agency workers fear the numbers on the 2006 list could be higher.
In one week in 2004, there were 171 people without a roof over their heads in the three counties. That was more than double the weekly toll in 2002.
The details emerged yesterday when Minister for Agriculture Mary Coughlan launched a full-time Simon service for the northwest in Bundoran, Co Donegal.
North West Simon Community chairwoman Eileen Magnier, RTÉ's Sligo-based correspondent, said every year, thousands in the area experienced some kind of a housing need.
"In 2006 no-one should have to live rough or in inappropriate accommodation. Yet the stark reality is that in 2004, almost 5,000 people were identified in the northwest as having a housing need.
"More recent research by North West Simon found that there is a particular housing problem among single people, especially men," she continued.
"In addition we have what you might term 'hidden homelessness', whereby many people are living in unsuitable accommodation which they really cannot call a home."
Simon North West, the organisation's eighth branch in the State, aims to establish a special skilled team to source appropriate accommodation for those in need and to provide a backup service to help them through rental and other difficulties.
Simon's regional development officer Claire McTiernan said: "We will not be providing traditional hostel-style accommodation but we will work with clients to ensure their long-term housing needs are met."
Ms Coughlan said it was vital that everybody in the region had a place they could call home. She said this would involve a "refocusing" of efforts to provide accommodation by the social, voluntary and private rented housing sectors.