Rents in Dublin are now almost 20% higher than their peak in the Celtic Tiger.
The latest report from property website Daft.ie shows rents across the country are up by almost 12% to the end of June.
The average national rent now stands at €1,159. Average rent in Dublin is €1,700 compared to €919 in Limerick.
Ronan Lyons from Daft says the number of properties available to rent is also at record lows.
"At one point, it had never gone below 5,000 - we broke through that, unfortunately, about a year ago," he said.
"It's been steadily decreasing really over the last five years and it's now gone below 3,000 for the first time, so it gives an idea - particularly with more renters now than ever before, there are actually fewer properties available on the market - of just how tough the market is."
Homeless charity Focus Ireland said that record rental prices are part of a 'perfect storm' forcing more families into homelessness.
The charity says the situation is particularly bleak for 1,800 children who are homeless and preparing to return to school in the coming weeks.
Roughan McNamara from Focus Ireland says tackling the issue of vacant properties is vital.
"What we're hoping the Government will do is have serious incentives for landlords to rent out properties to get more rental properties available, but also penalties for those who do not rent out their properties and we're hoping that the Vacant Home Strategy, and indeed Rebuilding Ireland, will take urgent action on this issue."