Barnsley's smoking research centre at the Cutting Edge pub in Worsbrough, has closed, following a visit from council officials.
Kerry Fenton, the Punch Taverns licensee at the pub came across a "loophole" in the smoking regulations, with the help of one of her regulars. She set up a separate room which permitted smoking in the interests of research.
Councillor Roy Miller, cabinet spokesperson for customer and neighbourhood services, said: "I can confirm that an officer from Regulatory Services has visited the Cutting Edge public house in Barnsley following reports of a 'smoking research centre' at the premises.
"A productive discussion with the licensee took place and an assurance has been given that the premises have now returned to being smoke-free. We will continue to monitor the situation."
Smokers had to fill in a questionnaire about how many cigarettes they smoked and whether they like a smoky atmosphere in pubs. Fenton said trade doubled since she started the "centre" last Friday.
Punch Taverns had condemned Fenton's decision and advised her to cease the activity immediately. A spokeswoman said: "We are pleased that our licensee has followed advice from both Punch and the Council and ceased this activity."