Extensive research on the Family Stress Model demonstrated the negative indirect impacts of parental cultural stress on adolescents' mental health via disrupted parenting. However, limited attention has been paid to testing how adolescents' cultural stress could affect parents' mental health through adolescent-reported parenting. According to Family Systems Theory, the family serves as an interdependent system, suggesting that adolescents' cultural stress can spill over and negatively influence parenting and their parents' mental health. Furthermore, prior studies have largely neglected the bidirectional link between parenting and mental health within the Family Stress Model. Thus, this study examined the associations among cultural stress, parenting (i.e., maternal warmth and hostility), and their mental health (i.e., anxiety and depressive symptoms) in mother-adolescent dyads across two waves. Participants included 595 mothers ( = 38) and adolescents (54% female, = 12) as dyads. The actor-effect results revealed that Mexican-origin mothers' and adolescents' cultural stress at Wave 1 (W1) were related to their own mental health at Wave 2 (W2) via their self-reported parenting at W1. Moreover, mothers' and adolescents' cultural stress at W1 were associated with their self-reported parenting at W2 through their self-reported mental health at W1. Partner-effect results indicated that mothers with higher levels of cultural stress at W1 were likely to report anxiety at W1, which may in turn influence adolescents' perceptions of more maternal hostility at W2. This study provides implications for family-based intervention programs that aim to both foster parenting and promote mental health outcomes in Mexican-origin mothers and their adolescents. (PsycInfo Database Record (c) 2025 APA, all rights reserved).