Only a quarter of Victorian national park users know campfires have to be extinguished with water, adding to the state's bushfire threat.
Parks Victoria asked 1000 Victorians whether a campfire should be put out with water or covered with soil or sand and 74 per cent selected the latter, incorrect answer.
"Once you light a campfire, you're legally responsible for ensuring that it is safe, does not escape, and is completely extinguished before you leave," Director of Fire and Emergency Services David Nugent said in a statement on Monday.
The campfire site should be cool to touch before being left unattended.
About 10 per cent of Victoria's bushfires are attributed to campfire negligence, the authority said.
"These survey findings are worrying, particularly given the number of people camping in Victoria during summer," Mr Nugent added.
As the state's temperatures remain high for another week, rangers have been targeting popular campsites, reminding visitors of their responsibilities.
The survey also found that only about half of park users know where and when they are allowed to light a campfire: only in designated fireplaces and not on total fire ban days.
Parks Victoria has responsibility for about 18 per cent of the state's land area.