January 30, 2026
SEOUL – The number of Korean adolescents who have tried smoking rises steeply as they move through school, a government study indicates, with a sharp jump between middle school and high school.
The cohort study tracks 5,051 students who were in sixth grade — the last year of elementary school — when the study began in 2019, with the latest data collected between March and October 2025.
According to the agency on Thursday, its panel survey found that the proportion who had smoked among the cohort, now aged 16-17 and in the 11th grade, had risen to 9.59 percent. That was up from 3.93 percent in ninth grade, the last year of middle school in Korea.
The increase in high school years was nearly 3 percentage points per year, and was almost as high as the total increase for all three years of middle school. The proportion who said they had tried smoking at the start of the survey, when they were still in elementary school, was 0.35 percent.
The proportion who were current smokers, defined as having smoked in the last 30 days, was 6.13 percent for boys and 2.17 percent for girls.
The spread of electronic cigarettes was identified as a major contributing factor, particularly among girls.
Among female students, the proportion currently using liquid-based electronic cigarettes exceeded that of conventional cigarette users, at 1.54 percent and 1.33 percent, respectively. The overall figures were 3.47 percent and 2.58 percent, as boys were still more likely to smoke conventional cigarettes.
The surrounding environment played a significant role in shaping these behavioral trends.
An analysis of predisposing factors showed that smoking initiation rates were meaningfully higher among students whose friends or family members smoked or expressed permissive attitudes toward smoking, with earlier ages of first exposure.
The survey also released interim findings on other health indicators, including alcohol consumption, skipping breakfast, nutrition, physical activity and smartphone use. All indicators showed a worsening trend as students grew older.
The Korea Disease Control and Prevention Agency said it plans to closely track participants over the remaining three years of the survey, expecting the data to provide important insights into the link between adolescent habits and adult health outcomes. The project has managed to retain 80 percent of the original members of the cohort, a relatively high level for a long-term study, according to the agency.
“The results serve as fundamental data for building policies and improving institutions that help adolescents grow into healthy adults,” a KDCA official said. “Because adolescent habits can shape health across the entire life course, coordinated efforts by schools, families and local communities are essential.”