Purpose The purpose of this study was to explore status and relationships of anger and its expression type to biopsychosocial health in Korean adolescents. Methods This cross-sectional study used four reliable survey questionnaires that measure anger, depression, resilience, and psychosomatic symptoms. Data were collected from 18,752 students of 36 middle schools and 23 high schools located in 23 administrative districts in Seoul, Korea. Results The Korean adolescents who completed the questionnaires indicated moderate level of trait anger. 45% of them demonstrated using one of three undesirable types of anger expression such as dysfunctional anger-in and anger-out, high level anger-in, or high level anger-out. Also, level of trait anger and types of anger expression were significantly associated with resilience, depression, and psychosomatic health status. Conclusion School-based mental health education such as anger management programs for Korean adolescents might be necessary to help them develop desirable and effective coping skills and strategies.