Rents have increased by 11.9% over the past 12 months, according to new figures from property website Daft.ie.
The average rent nationwide on the website now stands at €1,382, around €150 more than June 2006.
The survey confirms the trend evident in this week's inflation data from the central statistics office, which showed a 11.6% in rents over the past year.
Rent inflation is now at its highest level since the Daft Report was started in 2002
Daft said that over the last year, the supply of properties available for renting has fallen by about 20%.
'The fall in supply may represent some investors selling their properties and leaving the Irish rental market', the survey said.
In Dublin, rents are up by 12% on average, with rents in Cork and Limerick cities up 14% over the past year.
Growth has been somewhat slower in Galway and Waterford cities, where rents have typically risen by about 6.5%.
Although rents are increasing nationally, in certain market segments, rents are close to static. Outside the major urban areas, rents have increased by no more than 3% on average during the past year.
Brian Fallon of Daft.ie, said: 'With many people no longer able to afford to buy their own place, people are now extending their leases and staying in rented accommodation. As a result, rents are being forced upwards as there is more competition for fewer places to rent.'