The measures taken to cut the smoking rates have become widespread and affect some 3.8 billion people - just one half of world's population, says WHO. WHO urges the need for more action.
"If current trends continue, by 2030 tobacco will kill more than eight million people worldwide each year, with 80 percent of these premature deaths among people living in low- and middle-income countries," it added.
The WHO Report on the Global Tobacco Epidemic was launched in Uruguay as the health body sought to highlight the country's legislation against smoking that now faces a lawsuit by tobacco giant Philip Morris.
"The tobacco epidemic continues to expand because of ongoing tobacco industry marketing, population growth in countries where tobacco use is increasing, and the extreme addictiveness of tobacco that makes it difficult for people to stop smoking once they start," said Ala Alwan, WHO assistant director-general for noncommunicable diseases and mental health.
He noted that tobacco remains the biggest cause of preventable death worldwide, killing nearly six million people and costing hundreds of billions of dollars in economic damage each year.
Health warnings on cigarette packs protect more than a billion people in 19 countries, almost double the figures over the past two years, according to the report.
It said graphic ads were more effective than those only containing text, especially in countries with low literacy rates, and recommended that images be changed periodically to ensure they have an impact.
The size of the warning also has an effect, and the WHO noted that Uruguay had the largest images on cigarette packs, covering 80 percent of the surface, followed by Mexico (65 percent) and Mauritius (also 65 percent).
In Canada, the first country to introduce large health warnings on cigarette packs in 2001, three out of 10 former smokers said they were motivated to quit by the labels while a quarter said they helped them quit, according to the report.
Similar trends were also noted in Australia, Brazil, Singapore and Thailand.
Tobacco advertising and sponsorship, a favorite target of critics, saw comprehensive bans passed in Chad, Colombia and Syria between 2008 and 2010. And nearly 28 percent of the world's population -- 1.9 billion people in 23 countries -- are now exposed to national anti-smoking campaigns.
Some 425 million people in 19 countries -- six percent of the world's population -- are now "now fully protected against tobacco industry marketing tactics," 80 million more than in 2008, according to the WHO report.
"The number of people now protected by tobacco control measures is growing at a remarkable pace," said Alwan.
He attributed the progress to the growing impact of the WHO Framework Convention on Tobacco Control. Entered into force in February 2005, the treaty has 168 signatories and 174 parties.
While 101 countries ban tobacco print, television or radio advertising, both direct or indirect, the WHO considers the number to still be insufficient, noting that 74 countries (38 percent) have no or minimal restrictions on advertising.