Market research firm Ipsos asked 1,000 voters to pick their top three issues confronting Australia out of a list of 19.
The poll found that 41 percent of voters put "the environment" in their top three - up 10 percentage points since last month.
"Cost of living" and "healthcare" were the equal-second biggest concerns, each picked by 31 percent of respondents, while the "economy" featured in 25 percent of lists and "crime" in 21 percent.
The poll was taken after a month in which much of Australia was devastated by bushfires.
Daniel Evans, a social researcher with Ipsos, told Nine Entertainment newspapers that concern over the environment had been steadily rising before the bushfires.
"The environment is now clearly the top issue facing Australia," he said.
"The truth is that the tide of Australians' concerns about environment issues has been slowly rising for the past couple of years."
Younger generations were most likely to be concerned about the environment, with 48 percent of Millennials and 45 percent of respondents belonging to Generation Z including it in their top three.
"When we unpacked the reasons why Australians selected the environment, people mostly attributed their worry to climate change, drought and bushfire," Evans said.
"Some linked these topics, and others discussed climate change and drought in relation to natural resource management failings related to water and bushland. Comments were also made about waste, consumption, population growth and plastics."