A new survey that compares 140 cities, based partly on environmental credentials, rates an Aussie capital among the top five in the world.
Sydney is the fifth most liveable in the world, according to the new ranking which focuses on green space.
The list of the world's best cities to live in, which combines Economist Intelligence Unit (EIU) global "liveability" rankings with new criteria that examine "spatial characteristics", put Sydney fifth.
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Hong Kong was judged the most liveable city, followed by Amsterdam, Osaka and Paris, after additional criteria including urban sprawl, connection and proximity to other cities, and pollution were taken into account.
Sydney was the only Australian city to make the top 10.
Its ratings in these categories pushed it down from the number two rank in the classic EIU Liveability index, but gave Hong Kong a boost from number 10 to the top spot.
"Sydney scores well for having low pollution levels and lots of green space in the additional indicators," Jon Copestake, an editor for the EIU, said in a statement.
"Although it was hampered slightly because of the isolation of Australian cities and the urban sprawl of the city."
Hong Kong scored poorly for pollution and cultural assets, but scored on natural assets and low urban sprawl.
The index ranked 140 cities against one another.