Background: Longitudinal studies including parental distress when examining adverse health outcomes in adolescents with type 1 diabetes are lacking. This study examined whether parental depression and anxiety predict adolescent emotional distress and glycated hemoglobin A1c (HbA1c) 1 year later and whether a relation between parental distress and HbA1c is mediated by the level of parental involvement in diabetes care and by treatment behaviors. Methods: Longitudinal path modeling was applied to data from 154 adolescents and parents from diabetes centers participating in the Longitudinal study of Emotional problems in Adolescents with type 1 diabetes and their Parents/caregivers (Diabetes LEAP). At baseline and 1-year follow-up, participants completed measures of depression and anxiety. HbA1c was extracted from medical charts. Responsibility and treatment behavior questionnaires were completed by adolescents at baseline. Results: Baseline parental depressive and anxiety symptoms were not associated with 1-year adolescent depressive symptoms, anxiety symptoms, and HbA1c. Responsibility division and treatment behaviors did not mediate associations between parental emotional distress and 1-year HbA1c. Conclusions: Parental depressive and anxiety symptoms did not predict adolescent health outcomes 1 year later. Future studies may determine whether the link is present in case of mood/anxiety disorders or severe diabetes-specific distress, or whether adolescents are resilient in the face of parental distress. Impact: Adolescents with T1D are a vulnerable group in terms of psychological and health outcomes. Whether parental emotional distress (i.e., depressive and anxiety symptoms) is prospectively associated with adolescent emotional distress and/or HbA1c has been understudied.Our results show that parental distress was not related to adolescent distress or HbA1c 1 year later.Responsibility division and treatment behaviors did not mediate associations between parental emotional distress and 1-year HbA1c.Future studies could determine whether these links are present in case of mood/anxiety disorders or severe diabetes-specific distress, or whether adolescents are resilient in the face of parental distress.