Figures from the Private Residential Tenancies Board show that rents in Dublin are now higher than they were during the previous peak in 2007.
However the data show that the rate of growth in the cost of rented accommodation slowed in the final quarter of last year.
Rents outside Dublin are about 14.5% below their peak.
The economic crash caused rents nationwide to fall by 25%, hitting a bottom in 2012.
Since then they have risen, but at different rates in different parts of the country.
Rents in Dublin are 0.4% higher than their previous peak in 2007.
Information from more than 27,000 new tenancies that started in October, November and December show the pace of rental increase is slowing, and rents outside Dublin are now growing at a faster rate than the capital.
On an annual basis, rents were almost 10% higher across the country, representing increases in rent in Dublin of €124 a month for a house and €105 for an apartment, while outside the capital average monthly rent went up by €64 for a house and €67 for an apartment.
Call for government to re-open rental debate
The National Spokesperson for the Simon Communities has said the next government needs to re-open the debate around rent certainty
Speaking on RTÉ's Morning Ireland, Niamh Randall said aligning rents to the Consumer Price Index would mean that increases would be fairer and much more modest.
Ms Randall said people are being pushed out of the rental market into homelessness because they have nowhere else to go. She said this was not good enough.
She said it would take some time to see if measures which limit landlords' ability to increase rent have any impact in stabilising the market.
Ms Randall added that at the moment they are seeing the opposite of this, with landlords using the opportunity to increase rents.
Meanwhile, a Senior Research Officer with the ESRI has said there is a problem with affordability in the rental sector.
Speaking on the same programme, David Duffy said while the cost of accommodation is growing at a cost of 10%, peoples' incomes are not.
Mr Duffy said people are probably re-evaluating renting because they have been frightened off owner-occupancy following the crash, which left many people with homes in negative equity.
He said this means there is strong demand on the rental time at a time when supply is constrained, putting upward pressure on rents.