Sales of properties in regional Western Australia have fallen away sharply with more than one-fifth being sold at a loss, according to a nationwide report.

CoreLogic RP Data's latest report for the September quarter of 2014 showed regional WA had the highest loss rate at 22.5 per cent, with Queensland just behind at 22 per cent and Tasmania at 20 per cent.

The company's senior research analyst Cameron Kusher said a downturn in the mining boom was partly to blame for the poor performance in regional WA and Queensland.

"Those towns linked directly to the mining and resources sector have slowed very quickly, sales volumes have fallen away sharply, and prices have dropped extremely quickly over the last 12 or 18 months," he said.

While WA's capital city Perth enjoyed a relatively low loss rate of 6 per cent in the quarter, Mr Kusher said it would likely become one of the worst performing cities in the country, due to slowing capital growth and easing rental markets.

"My view would be that over the coming quarter you'll see that proportion of loss-making sales in Perth start to escalate as well," he said.

"Probably not up to that 22.5 per cent mark that we're seeing in regional WA, but I do think that there'll be some growing weakness right across Western Australia over the next 12 months."

'Astronomical growth' in mining towns since 2001, 2002

But it was not all doom and gloom for WA with regional areas recording the highest rates of sales making more than 100 per cent profit, with 37.4 per cent of homes selling for more than double the amount they were purchased for.

Perth closely followed the state's regions, making it the best performing capital city in the country for big profits, with 37 per cent of homes sold for more than double what they were bought for.

Mr Kusher said that was due to an overall long-term property rise in WA, with properties that were held for 10 to 15 years or more selling for a big profit.

"In the mining towns, if you were buying in 2001, 2002, and selling now, obviously you might be selling a little bit less than what it was at the peak but you've seen astronomical growth over that period of time," he said.

"So really I think it highlights that buying and selling in residential property is all about timing.

"If you look at the loss-making sales, the typical length of ownership of those homes is around five years, whereas people who get double what they previously purchased the property for have typically held for more than 15 years.

"It really reiterates that buying and investing in the housing market is more of a long-term strategy than a short-term strategy."

CoreLogic said the average length of ownership for loss-making properties across Australia was 5.7 years, versus 9.9 years for real estate that sold at a gross profit.