Services by the housing charity Threshold saved over 11,000 people from homelessness last year.
Its annual report shows it answered an average of 321 calls every day from tenants needing support.
The latest Government figures show that 10,514 people were living in emergency accommodation in October.
But Threshold claims its report shows that a further 11,500 people were only kept in their homes last year because of interventions by them.
It says of the notices of termination dealt with, it found that over half of them were invalid.
Three-quarters of notices of termination issued to tenants in 2018 did not arise from any assertion that a tenant had perpetrated any wrongdoing.
While the single biggest reason given for notices of termination was that the property was to be sold - the incidence of this was higher than in 2017.
Threshold also represented 254 clients at the Residential Tenancies Board in 2018: almost three-times the number in 2017.
And there was an increase in the number of cases of discrimination against tenants in receipt of Housing Assistance Payment (HAP) in 2018.
Under the law, a landlord cannot discriminate against people on the grounds that they are in receipt of rent supplement, HAP or other social welfare payments.
Threshold supported six clients to take cases for discrimination to the Workplace Relations Commission (WRC).
The charity's chairperson, Aideen Hayden, said: "When these figures are published every month, people can often feel powerless to do anything about the housing and homelessness crisis.
"This report shows there are real solutions.
"Prevention services really work; supports in the community can keep vulnerable people in their homes; and a long-term social housing building programme is required.
"Lack of long-term planning got us here. Proper planning for the future can get us out of here", she said.
According to Threshold CEO John-Mark McCafferty: "In the year 2018 alone we carried out 67,710 actions on behalf of tenants to fight for their homes.
"Whether it was making a call, providing legal representation or helping someone to navigate the complex laws underpinning tenants' rights.
"Because of this work, we stopped 5,161 households from becoming homeless.
"That's 4,451 children and 7,111 adults who would have lost their homes without Threshold's support."
"There are also many hidden homeless people who are couch surfing, staying with family and friends, and living in very overcrowded conditions.
"These people are not showing up in homelessness figures, but they are facing a housing crisis and need solutions."