A report from the Residential Tenancies Board (RTB) shows the average rent being paid across the country is now €1056, up from €965 a year earlier.
It represents a 9.5% increase over the last year and coincides with the publication of homeless figures which show a record high for the numbers in emergency accommodation.
In Dublin, the average rent was at €1,518, with the average for the greater Dublin area (Meath, Wicklow and Kildare) at €1,086.
Outside of the Greater Dublin Area, the average rent was €811.
The national housing charity, Threshold has reiterated its call for the introduction of a mandatory rent register and proper enforcement of legislation.
Its chief executive, John-Mark McCafferty, said: "A mandatory rent register would create clarity for tenants.
"A property price register already exists in this country so we see no reason why a similar resource could not be developed for renters, who continue to find themselves in a very vulnerable position.
"Without disclosing the names of either the tenants or the landlords, a register would provide clarity to renters as to the level of rent they should expect to pay for a particular property.
"Enforcement of rent pressure zone legislation is clearly a problem and we find it ridiculous that the RTB won’t put in place this very simple measure, which would be hugely beneficial."
Threshold chair, Dr Aideen Hayden, added: "It is shocking that homeless figures continue to rise in this country and the only long-term solution to this is the development of social housing on a large scale.
"Recent figures from the Dublin Regional Homeless Executive show that the private rented sector is a huge driver of homelessness in the region, with nearly half of the newly homeless from June to August 2017 coming from the private rented sector.
"It is in crisis and it is not going to improve until legislation is enforced and tenants are aware of their rights and landlords of their obligations".