The proportion of children exposed to second-hand smoke at home has almost halved in the last five years.
An NHS Scotland and Edinburgh University review of the Scottish Government's tobacco control strategy also found a "downward trend in smoking prevalence".
It also warned smoking continues to be a bigger problem in more deprived areas.
The Scottish Government's national tobacco strategy, Creating a Tobacco Free Generation, was published in 2013.
The review found the strategy had a positive impact, with smoking rates among adults now at 20% compared to 31% in 2003.
The proportion of children exposed to second-hand smoke at home fell from 11% to 6% between 2014 and 2015.
Smoking rates in the most deprived areas were found to be at 35%, compared to 10% in the most affluent areas.
'Scotland has some of the most progressive tobacco control policies in the world.'Dr John McAteer, University of Edinburgh
Dr Garth Reid, principal public health adviser at NHS Health Scotland said: "The evidence shows the positive impact of tobacco policy, ranging from the display ban which put tobacco out of sight in small shops and supermarkets to the introduction on smoke free NHS grounds.
"Yet, levels of smoking are still highest in Scotland's most deprived areas, with 35% of people living in the most deprived areas smoking compared to ten percent in the most affluent areas.
"It is clear that further action to reduce inequalities in smoking is necessary if the aim of making Scotland tobacco-free by 2034 is to be achieved."
Dr John McAteer, senior research fellow at Edinburgh University, said: "One of the aims of the 2013 tobacco control strategy was to reduce second hand smoke exposure among children by 2020.
"The most recent Scottish Health Survey shows that second hand smoke exposure fell from 11% to 6% between 2014 and 2015.
"This equates to 50,000 children having been protected from the harms of daily second-hand smoke exposure at home.
"Scotland has some of the most progressive tobacco control policies in the world, and Scottish smoking rates have fallen from 31% in 2003 to 21% in 2015."