Property Investors in Perth are taking in $10 a week less as the vacancy rates rise.
The Real Estate Institute of Western Australia says March quarter figures show rents are about $450 a week for a house and $420 for an apartment or villa.
Its president, David Airey, says the metropolitan median rent has dropped $30 since March last year and he expects the vacancy rate to rise further in winter.
"The Perth vacancy rate lifted to 4.4 per cent for the first three months of the year, due to falling population growth, the volume of new dwellings on the market and the number of former tenants who became first home buyers while interest rates are low," he said.
The institute says a vacancy rate of three per cent is normal.
Mr Airey says the number of rental properties on the market has increased to about 7080 - up from 5140 on the same time last year - but rents have remained steady in the three months to April.
Perth rents peaked at $475 a week in mid-2013, but have since fallen 9.5 per cent as supply surpassed demand.