Almost every pub and club in Wales has complied with the ban on smoking in public places brought in six months ago, say health officials.
Two dozen premises were fined for allowing a smoker to light up
Wales's chief medical officer said only 25 penalty notices had been issued since the ban began on 2 April.
Dr Tony Jewell said: "A number of licensees have commented that trade has never been busier."
However, landlords' spokesman Aneurin Jones said: "I think the majority of people have lost business over it."
Figures released by the assembly government show almost 99% of licensed premises in Wales are complying with the smoking ban.
Of the 25 penalty notices issued, most were for smoking in a smoke-free area, with one for incorrect signage.
Officials are claiming public support for the ban has grown since it was brought in, with backing rising from 71% in February 2006 to 80% in May.
Dr Jewell said the ban was on course to deliver health benefits similar to those seen in Scotland since its ban 18 months ago.
He said: "If Wales benefits to the same extent we could expect a 17% reduction of hospital admissions for patients with acute coronary syndrome amounting to 958 admissions.
The legal age for buying tobacco rose to 18 at midnight
"The ban will help to cut the number of deaths from second-hand smoke. Every year there will be an estimated 400 fewer premature deaths of non-smokers.
"I am pleased that the introduction the smoking ban has gone smoothly and I hope that individuals and businesses will continue to comply so that we ensure we maximise the health benefits of the ban."
But Mr Jones, of Licensed Victuallers Association Wales, who runs a hotel in Llanberis, Gwynedd, said: "I don't know who's winning in the end.
"I'm a non-smoker myself and it's much nicer now to be in the public bar but I'm not sure if it's going to make people healthier.
"The ones that are not coming to the pub now are smoking and drinking among their children, at home."
Last month, doctors in Wales called on the assembly government to ban cigarette vending machines and packets of 10 as a way to cut underage smoking.
At midnight on Sunday, the minimum age for buying tobacco products increased from 16 to 18 in a bid to cut the number of young smokers.