Rental growth remained largely flat during the June quarter, according to Australian Property Monitors' Rental Price Series Quarterly Report.
Nationally median rent for houses rose by just under one per cent while the median rent for units rose 3.5 per cent.
Sydney was the only major capital city to record rental growth for both houses and units, resulting in a weekly median rent of $480 for houses and $440 for units.
The rest of the major capital cities - with the exception of Canberra - saw rents falling for houses or remaining stable, with units recording only moderate rental growth in the quarter.
Australian Property Monitors economist Matthew Bell said higher vacancy rates in Brisbane and Perth have translated into lower annual rental growth compared to Sydney and Melbourne, where vacancy rates remain relatively low.
"Although vacancy rates remain low in most capital cities and unemployment continues to fall, the quarterly figures indicate that landlords accepted renters may not have been as willing to agree to rental increases in the June quarter," he said.
"Higher mortgage costs have hit some landlords hard, but weak consumer spending and concerns over the global economy, reflected in the fall in the local share market, has meant that landlords have been conservative in raising rents compared to the March quarter," said Mr Bell.
