The smoking ban in Scotland has seen a 10% decrease in sales and a 14% fall in customers in pubs, according to a new study.
The study carried out by Oxford University Press on behalf of the International Epidemiological Association compared sales before and after the ban at 2724 pubs - 1590 in Scotland and 1134 in northern England - where smoking is still permitted.
The study's authors say this is the first major look at the smoking ban outside of the US - where trade has remained fairly constant.
Our study suggests that the Scottish smoking ban had a negative economic impact on public houses Report for International Epidemiological Association
The report says: "These studies have mostly found no negative economic effects of such legislation on the hospitality sector in the long run.
"However, differences in the social use of public houses in Great Britain in comparison with the US may lead to different findings."
"Our study suggests that the Scottish smoking ban had a negative economic impact on public houses … due in part to a drop in the number of customers.
"The short-term impact of the ban did not lead to more customers coming into pubs due to the smoke-free atmosphere, and presumably did not lead smokers to spend more money on drink or food instead of smoking."
The study backs anecdotal evidence from licensees north of the border.
Paul Waterson, SLTA chief executive, told the Glasgow Herald: "The figures from the drinks suppliers are showing growth in drink sales in Scotland's pubs is running at less than half that in England. Smokers are spending less time in pubs since the ban took effect."
Waterson said that, before the introduction of the ban, anti-smoking groups had argued that pubs would not lose out, as non-smokers would be keen to enjoy a drink in a smoke-free environment.
"We thought that was nonsense at the time and it is still nonsense," he said.