More than 8,500 people were prosecuted last year for puffing away indoors - the most since a smoking ban took effect seven years ago.
The figure is encouraging, a medical academic says, although the number of prosecutions represents fewer than half the complaints lodged last year.
Lam Tai-hing, chair professor of community medicine at the University of Hong Kong, attributed the record figure to tighter enforcement action rather than a rise in offender numbers.
"From the experiences of different parts of the world, the number of offenders will not increase unless there is a lack of enforcement," Lam said.
A smoking ban was introduced in 2007 in restaurants, indoor workplaces, karaoke venues, shopping centres, markets and other outdoor public areas. Covered public-transport terminals went smoke free in 2009, followed by open-air interchanges in 2010.
Smoking in shops or malls led to 19 per cent of the prosecutions, followed by amusement arcades, with 18.7 per cent.
Lam encouraged the public to persevere in alerting the office to errant behaviour, even when repeated complaints resulted in no prosecution.
But penalties were just one aspect of tobacco control, he said, with education also important in helping smokers quit.
A restaurateur said he saw no obvious impact on business as a result of the ban, despite some restaurants having complained of fewer customers.
"The problem is with smokers having to go out onto the street to light up," said Simon Wong Ka-wo, president of the Federation of Restaurants and Related Trades. "They are noisy and throw cigarette butts everywhere, causing a nuisance."
The staff of restaurants and other venues were loath to ask customers to stub their cigarettes out as things might turn nasty, Wong said. Some had been physically attacked by smokers, he said. The tobacco office also had its hands tied, he added, with too few enforcement officers who might not arrive in time to catch offenders in the act.