Plain packaging for cigarettes made smokers more likely to quit in the year after it was introduced, the most comprehensive research on the legislation to date shows.
The Cancer Council Victoria-led research found that plain packs and health warnings "encourages thinking about quitting and quit attempts".
It also reduces the appeal of packs among teenagers.
And researchers found no evidence to back the claim that the laws have led to an increase in the sale of illicit cigarettes.
The research was presented at the World Conference on Tobacco or Health in Abu Dhabi on Thursday.
To coincide with the conference, 14 papers on the topic have been published in a supplement in the British Medical Journal.
The findings are based on interviews with over 5000 Australian adult smokers carried out before and after plain packaging was introduced in December 2012 and a separate survey of 6000 high school students.
Cancer Council Victoria's Professor Melanie Wakefield said the outcomes of the legislation are extraordinary.
"Plain packaging achieved its specific objectives within its first year after implementation, which is quite stunning," she said.
"Our research should give confidence to other countries who are interested to go forward with plain packaging."
The research will confirm the tobacco industry's worst fears about the effectiveness of plain packaging, said Cancer Council Victoria CEO Todd Harper.
"What we can expect now is the tobacco industry will increase their efforts globally to try and persuade government to try and not introduce plain packaging," he said.
The UK's House of Lords is due to vote this week on introducing similar legislation.
If they back last week's vote by MPs, plain packaging will be introduced in the UK in May 2016.
Ireland recently voted to introduce similar legislation.
• The research found about one in five smokers attempted to quit in the months before the change. After plain packs were introduced this increased to more than one in four.
• Plain packaging is associated with more persistent quitting thoughts and quit attempts.
• The new larger health warnings on the plain packs increases adult smokers' motivation to quit.
• In adolescents, the combination of plain packaging and larger health warnings create a less positive brand image and make tobacco less appealing.
• Researchers found no evidence of an increase in the use of unbranded illicit tobacco following the implementation of the legislation.