PROJECT SUMMARY/ABSTRACT Physical inactivity is associated with poor asthma control and lower quality of life. Rates of physical inactivity, asthma, and asthma mortality among Black girls are higher than their White counterparts. Our formative work identified barriers to physical activity among Black women with asthma and led to the development of a culturally tailored physical activity intervention for Black women with asthma (ACTION: A lifestyle physical activity intervention for minority women with asthma). The goal of this study is to adapt the intervention for Black girls with asthma using a dyad approach. We will engage urban Black girls (8-12 years) with asthma and their mothers in interviews to understand how the ACTION intervention should be modified to fit the needs of urban Black girls with asthma. We will modify and then pilot test the intervention (Mothers and Daughters in ACTION). This study will provide the first ever evidence of a family-based lifestyle physical activity intervention culturally tailored for urban Black girls with asthma, a population that is understudied yet plagued by low levels of physical activity and poor health outcomes. We have assembled a multidisciplinary team that has the necessary expertise to carry out the proposed study, including in asthma, physical activity, dyad interventions, program development, qualitative methods, as well as observational and randomized studies. This award will provide the infrastructure and data about feasibility and preliminary efficacy to apply for funding (NIMHD R01 RFA-MD-22-007) to rigorously test the efficacy of the Mothers and Daughters in ACTION and advance management of asthma in minority populations living in low-resourced urban environments.