Background:
According to the Juvenile Protection Act in Korea, tobacco is regarded as juvenile harmful substance, and no one is allowed to sell, rent or distribute tobacco products to adolescents. Furthermore, Framework Convention on Tobacco Control Article 16 prohibits the sales of tobacco products to minors. In this study, we investigated the tread and associated factors of easiness to purchase cigarettes among Korean adolescents from 2005 to 2016.

Methods:
The analyses were based on the data of the Korea Youth Risk Behavior Web-based Survey. We estimated the trend of easiness to purchase cigarettes from 2005 to 2016 and evaluated associated factors by multivariate logistic regression analyses after adjusting for year, sex, grade, geographic area, self-perceived socioeconomic status, problematic drinking in last one year, quit attempt in last one year, current smokers within family members, current smokers within close friends, pocket money, and average amount of cigarettes smoking.

Results:
Easiness to purchase cigarettes decreased from 83.9% in 2005 to 71.4% in 2016, but still in very high level. The odds ratios of easiness to purchase cigarettes greater in adolescents with higher grade, those who smoke higher amount of cigarette smoking in a day, those who live in metropolitan and big cities, those who had problematic drinking in last one year, and those who have current smokers within close friends.

Conclusions:
Although easiness to purchase cigarettes among Korean adolescents decreased, more than 70% of Korean adolescents can purchase cigarettes without an effort. Low enforcement must be strengthened in order to prevent adolescent smoking.