Provisional statistics show there were more than 103,000 quit attempts made with the help of smoking cessation services in Scotland last year, a 13% reduction on the figure for 2012.
"This is the first decrease seen in recent years and could be partly explained by the rise in use of electronic cigarettes," the latest statistics report said.
The official figures for 2013, published by ISD Scotland, found that an estimated 10% of the adult smoking population made an attempt to quit with an NHS service last year.
Women accounted for 57% of all attempts, while people aged 45-59 made up the highest proportion.
A recent survey found that the use of electronic cigarettes among smokers has increased by more than five times in the past four years.
A poll by the charity ASH Scotland also found nearly half of smokers have tried e-cigarettes, increasing from 7% in 2010 to 45% by 2014.
The survey further showed 17% of smokers were using the devices this year, compared to just 3% in 2010.
E-cigarettes, which deliver nicotine vapour instead of tobacco smoke, are now used by 3% of adult ex-smokers.