Rents have risen by 9.8% across the country, according to a new Daft.ie report.
It shows the average monthly rent nationwide during the last three months of 2018 was €1,347.
That compares to €1,982 in Dublin - a rise of 8.8% in the year to December.
In Limerick and Waterford cities, however, rents were 16% and 16.7% higher than a year previously.
Galway rents rose by 13.1%, while in Cork rent prices were up 11.4%.
According to the report, there was a 'rare improvement' in availability of rental accommodation at the end of 2018, meaning a slight easing in rental inflation.
On January 1st, for example, there were 3,641 properties available to rent nationwide - up 11% on the same date in 2018.
Ronan Lyons, author of the report and economist at Trinity College, explained that the rate of rent increases is slowing in places.
He observed: "If you look for example in the Dublin rental market, the rate of inflation has fallen from 11% in 2017 to below 9% in 2018.
"Across the country there are other examples of the same kind of thing - so, for example, in Donegal the rate of inflation has fallen from above 6% to close to 5.5%.
Mr Lyons stressed that there's a continued need for more homes.
He noted that current efforts are focused on 'one-offs and estate housing', whereas the overwhelming need is for apartments.
He added: "It remains to be seen, therefore, whether the modest improvement in conditions over recent months continues.”
Responding to the latest figures, the Simon Communities said stronger tenant protections are needed as many people are continuing to be priced out of the rental market.
Spokesperson Paul Sheehan argued: "Enhancing security of tenure has to be an urgent priority so that people already housed can keep a roof over their heads and have greater certainty in their daily lives.
"People trapped in emergency accommodation need secure and affordable homes, with support where needed."