This study conducts a screening of mental health (MH) among adolescents and examines the relationship between MH, knowledge of mental health, and healthy lifestyle. The study sample includes 571 high school students in Da Nang City, who were surveyed using a questionnaire on knowledge, attitudes, and behaviors related to mental health, along with indicators of a healthy lifestyle. The results show that a large proportion of students have low knowledge about MH, reflecting a lack of awareness regarding the importance of mental health. While knowledge of MH does not show a significant correlation with the mental health status of adolescents, a healthy lifestyle demonstrates a clear and meaningful relationship with mental health and is a significant predictor of students' mental well-being. The study recommends the implementation of educational programs to raise awareness about mental health among adolescents and encourages the promotion of a healthy lifestyle to support the improvement of mental health.