Only 13 people have been caught lighting up illegally in London since the smoking ban came into force on 1 July, according to initial figures from councils in the capital.
Enforcement officers have visited more than 6,000 pubs and clubs in London to monitor implementation of the legislation that outlawed smoking in public places.
But they found the only real problem was that some operators had not put up the necessary warning signs, according to the Evening Standard.
None of the 13 people caught smoking and no premises have received anything more than a verbal warning from officials, the newspaper said.
Officials from Islington council made the most visits by any borough - around 1,200 - and found just three breaches, meaning 99.8% of venues were complying with the law.
A spokesman for the Department of Health said: "We welcome the positive feedback we are already receiving about the new smoke-free law.
"Although it is still early days, we are very pleased with how favourably it has been received by the public.
"We have not had official data from councils but know that, not only in London, but across England levels of compliance are high and the need for councils to take enforcement action has been minimal."
By Daniel Thomas