This study examined the structure, reliability, and convergent validity of the adolescent version of the Mental Health Continuum-Short Form (Dutch MHC-SF-A), a self-report questionnaire for positive mental health assessment. This questionnaire was completed by 459 Dutch adolescents (178 boys and 281 girls) between the ages of 11 and 18 years at baseline and at a 4-week follow-up. Results revealed the 3-factor structure in emotional, psychological, and social well-being, a high internal reliability and a moderate test-retest reliability. Findings suggest that mental illness and well-being represent two related but distinct continua of mental health. Fostering adolescents' well-being is important. Promoting positive emotions, creating a supportive and loving parent-adolescent relationship, and a supportive school environment will contribute to this.