In a statement, the organisation said they are calling on governments to rate films portraying tobacco use, as unsuitable for children "in a bid to prevent children and adolescents from starting to smoke cigarettes".
The advice, presented in the "Smoke-free movies: from evidence to action" report, also suggested producers should display strong anti-smoking advertisements before films which feature tobacco use.
Dr Douglas Bettcher, WHO’s director for the department of prevention of non-communicable diseases said: "With ever tighter restrictions on tobacco advertising, film remains one of the last channels exposing millions of adolescents to smoking imagery without restrictions.
"Smoking in films can be a strong form of promotion for tobacco products."
WHO believes an adult rating will prevent children taking up smoking
The report, which was released on 1 February 2016, referenced previous research to show evidence of effect smoking in films has on children.
Smoking was found in 44% of all Hollywood films released in 2014, as well as being found in 36% of films that were rated for young people.
In the same year, the report stated, the US Centers for Disease Control and Prevention estimated that in America alone, exposure to on-screen smoking would recruit more than six million young smokers in America, of which two million would "ultimately die from tobacco-induced diseases".
A study conducted three years earlier found a similar correlation between films showing smoking and children taking up the habit in the UK.
Researchers from the University of Bristol analysed more than 5,000 15-year-olds in Great Britain and Northern Ireland. They found those who saw the most films with smoking imagery were 73% more likely to have tried smoking than those who had seen the fewest, according to WHO.
The NHS also reported this study, stating: "Reducing smoking in young people is an important issue and it is probable that role models in films play a part."
WHO also reported that tobacco imagery was found in films produced in six European countries (Germany, Iceland, Italy, Poland, the Netherlands and the United Kingdom), and two Latin American countries (Argentina and Mexico) since they began their research.
The report gave four recommendations:
1. Requiring age classification ratings for films with tobacco imagery to reduce overall exposure of youth to tobacco imagery in films.
2. Certifying in movie credits that film producers receive nothing of value from anyone in exchange for using or displaying tobacco products in a film.
3. Ending display of tobacco brands in films.
4. Requiring strong anti-smoking advertisements to be shown before films containing tobacco imagery in all distribution channels (cinemas, televisions, online).
Researchers stated teens exposed to these lyrics and images are "more likely to start smoking or drinking", which poses a "significant health hazard".
The study, published in the Journal of Epidemiology & Community Health, found 13- to 15-year-olds were most exposed and girls were exposed to more of these images and lyrics than boys.
"With these levels of exposure, in one year, music videos would be expected to deliver over four billion impressions of alcohol, and nearly one billion of tobacco, in Britain alone," the researchers wrote.
In their advice, the researchers recommended: "Owing to the obvious health implications for adolescents, we suggest that overly positive portrayals of both alcohol and tobacco in music videos should be included in both the drug misuse and dangerous behaviour presented as safe rating categories."