Official figures show the value of retail sales rose a seasonally-adjusted 0.6% to more than $18 billion in the September quarter, compared with the previous quarter.
Excluding price changes, the volume of retail sales rose 0.3%.
Excluding sales in vehicle-related industries, core retail sales actually fell a tenth of a percentage point.
A rise in spending on cars, hardware and furniture helped to offset a fall in clothing and accommodation.
ANZ Bank senior economist Mark Smith says the figures were weaker than market expectations.
"Core retail spending had been quite strong in the first half of the year - we're definitely seeing signs of de-celeration in the September quarter, with core volumes falling. It could just be consumers giving their wallets a bit of a breather after a fairly hectic period."
Spending on "durables" - such as refrigerators, cars, or mobile phones - remained strong, with spending volumes in this category up nearly 10% for the year.
"Consumers' love affairs with major purchases are showing little signs of abating so far," Mr Smith says.
