The Australian Government's constitutional victory over major tobacco companies is expected to unleash a new international move against cigarette marketing.
The High Court's finding that plain packaging laws - due to come into force in December - are legal has set a precedent that other countries including New Zealand, Britain and India are interested in following.
In April the New Zealand Cabinet agreed in principle to follow Australia, subject to public consultation.
Tobacco companies have accepted the High Court decision and undertaken to comply with the new laws requiring plain green packaging, large and graphic health warnings and brand names confined to a small generic font.
But the law still faces challenges overseas, with the Dominican Republic, Ukraine and Honduras filing requests for consultations under World Trade Organisation rules, claiming that it breaches international agreements on intellectual property rights and barriers to trade.
National Heart Foundation chief executive Lyn Roberts said the High Court decision was a significant milestone in the global fight against the "carnage" caused by smoking.
"Australia has been a world leader in reducing smoking rates ... and this win today is a signal across the world that we are on the right track," she said. "Many nations have been watching this case closely, and many will now seek to implement their own legislation."
Council on Smoking and Health president Mike Daube said the decision was the global tobacco industry's worst defeat, while Public Health Association chief executive Mike Moore was pleased that even the massive resources of a global industry could not buy government policy or High Court decisions.
Plain packaging is the latest tightening of anti-tobacco measures in Australia, which already has some of the world's toughest laws that range from bans on smoking at beaches, parks, public spaces and restaurants to display, advertising and sponsorships.
The decision to introduce plain packaging in a green hue calculated to deter buyers - especially the young - and with horrific pictures of possible consequences was fought bitterly by tobacco giants.
Four companies, British American Tobacco, Japan Tobacco International, Philip Morris and Imperial Tobacco Australia, argued that plain packaging was unconstitutional because it stole copyright by extinguishing brands and logos without compensation.
But the High Court accepted the Government's argument that it had the right to regulate tobacco as it did other harmful products and that by controlling only what could appear on packaging it had not removed intellectual property rights.
The court, which also ordered the tobacco companies to pay the Government's costs, will release the reasons for its decision later this year.
Attorney-General Nicola Roxon, who promoted the law as Health Minister, said the Government was proud of a move that would help to reduce smoking.
"This is good news for every Australian parent who worries about their child picking up an addictive and deadly habit," she said.
Health Minister Tanya Plibersek added: "This is a victory for all of those families who have lost someone to tobacco-related illness. For anyone who has lost someone to smoking, this one is for you."
But British American Tobacco Australia spokesman Scott McIntyre said the industry was "extremely disappointed" by a decision upholding a bad piece of law that would have serious unintended consequences.
He said the illegal cigarette black market would grow further when all packs looked the same and were easier to copy.
"Last year the amount of illegal cigarettes smuggled into the country and sold on the streets of Australia tripled. Crime groups are pocketing hundreds of millions of dollars while avoiding tobacco excise to the tune of A$1 billion."