New census figures from across the ditch show 483,400 people living in Australia were born in New Zealand.
That is an increase of almost 100,000 - or the equivalent of about a 25 per cent jump - in the number of Kiwis living there since the last count in 2006.
It also means there are now more New Zealand-born people living in Australia than there are living in either Christchurch or Wellington.
Many who leave New Zealand shores do so because of the promise of more jobs, better pay and warmer weather.
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The new figures reflected a longer and more sustained migration than any in the past, said professor Paul Spoonley, a sociologist at Massey University.
"We have reached an important tipping point as many of the migrants already have family members living in Australia," he said. "People want to be near their kids and grandkids and now we are seeing them joining relatives who have moved there for a better standard of living."
Spoonley believed the true number of Kiwis who had hopped the Tasman was likely to have passed the 500,000 mark.
"A lot more people have migrated since the Census figures were collected last year and a lot of them have gone from Christchurch, in the wake of the big earthquake."
The New Zealand High Commission in Canberra and the New Zealand Consulate-Generals in Sydney and Melbourne noted an increasing number of Kiwis wanting help to return home.
Most Kiwis who moved to Australia were issued with a non-protected special category visa, which meant they could live and work there as long as they wished, as long as they remained of good character.
However, this meant limited access to Australian health, disability, social and education support.