Introduction: Cardiovascular health (CVH) distribution and its impact on vascular health, particularly among Asian adolescents, is unclear. We aimed to examine (1) the CVH distribution and (2) the association between CVH and carotid intima-media thickness (cIMT) among Korean adolescents. Methods: We included 666 students (mean 15.4 years at baseline, 49.2% girls) from the JS High School cohort, a prospective single-school cohort. All participants completed a set of health examinations in a 2-year span. We classified and described participants’ CVH per AHA Life’s Essential 8, excluding diet and sleep. A cumulative CVH score was calculated as the total score of each visit (0-100 points for six components; cumulative score ranged 0-1200 points) and classified into quartiles. The association between cumulative CVH score and follow-up cIMT was assessed using the multivariable logistic regression model. Results: Baseline, follow-up, and cumulative CVH scores ranged from 300-600, 255-600, and 555-1180 points, respectively. Most participants achieved optimal nicotine exposure and blood glucose, whereas few achieved optimal physical activity. (Figure A) A sex difference was observed in blood pressure; 78.4% (257/328) and 36.6% (90/338) of girls and boys, respectively, maintained the optimal level. Participants with lower baseline or follow-up CVH scores tended to have greater cIMT. (Figure B) Gradually reduced odds for increased cIMT were observed according to higher CVH scores (Figure C). Conclusion: Among Korean adolescents, achieving higher cardiovascular health was associated with thinner cIMT. Our findings highlighted a disparity in the CVH distribution. Future studies should include information on diet and sleep.