The vast majority of homes in Rent Pressure Zones across the country have failed to meet minimum housing standards.
The worst offenders were properties in Limerick City and County Council, Galway County Council and Louth County Council.
None of the private rentals inspected passed the minimum housing standards.
Figures supplied toby local authorites with RPZs show that 16,441 private rental properties were inspected last year, with 90% not meeting the required standard.
Dublin City Council inspected the most homes, of which more than 95% failed to meet the standards.