Abstract Background The aim of this study was to examine the association between parents’ mental disorders and adolescents’ self-rated health, using both subjective and objective assessment of parents’ mental health status. Methods This cohort study was based on the Danish Future Occupation of Children and Adolescents cohort. Study population 25,891parents (biological parents or registered guardians) linked to 13,067 adolescents. Survey data were merged with register data on parent mental health, and logistic regression was used to analyse association between the register- and self-report data on parents mental health, and self-rated global health among their offspring. Results Adolescents’ self-rated health was associated with their parents’ mental disorders, showing an unadjusted OR of 1.5 (95% CI 1.4-1.6) when assessing parental mental disorders using ICD-10 diagnoses and an unadjusted OR of 2.0 (95% CI 1.8-2.2) when using the adolescents’ self-reported measure on the parental mental disorder. Adjustment for adolescents’ sex, adolescents’ mental disorders during childhood, parental education, and parental labour market attachment led to a decreased association between parents’ mental disorders and adolescents’ self-rated health in both analyses with an adjusted OR of 1.2 (95% CI 1.1-1.4) when assessing parents’ mental disorders using ICD-10 diagnoses and an adjusted OR of 1.8 (95% CI 1.6-2.0) when using the adolescents’ self-reported measure on parental mental disorder. Conclusions This study documents a clear pattern in mental disorders across generations and that parental labour market attachment as well as mental disorders in earlier life phases are risk factors for developing mental disorders in adolescence. The results point to the importance of public health interventions aimed at the more vulnerable group of adolescents, where mental health problems are observed over two generations. Key messages • There is a clear pattern in mental disorders across generations. • Parental labour market attachment are risk factors for developing mental disorders among their offspring.