Abstract Background: Latino patients with advanced cancer and their caregivers are an understudied and underserved population that experiences high levels of psychological distress and impaired quality of life. As part of a larger effort to culturally adapt a mindfulness intervention for this population, this study qualitatively explored sources of support and strain, with a particular focus on the social context, among Latino patient-caregiver dyads undergoing cancer treatment. Methods: Twenty Latino patients undergoing treatment for a metastatic solid malignancy and their family caregivers were recruited from a county hospital and participated in semi-structured interviews. Interviews were conducted by a trained, bilingual and bicultural staff member and explored participants’ cancer-related experiences, psychosocial needs, and sources of support. Interviews were digitally recorded, transcribed verbatim by a professional external vendor, and translated into English, where applicable. Atlas.ti was used to conduct a thematic descriptive analysis. Results: Patients (55% male) and caregivers (60% female) were predominantly born outside the U.S. (93%) and reported low levels of education (59% < high school graduate) and income (63% household income < $30,000). Preliminary analyses revealed how family can be both an important source of support and strain. Many participants described how the cancer diagnosis brought the family closer while others shared negative experiences including discrimination and distancing by family members. Participants’ religious faith, their church community, friends, work colleagues, and other cancer patients were highlighted as additional sources of support. Reported strains included financial stress (e.g., loss of income, healthcare costs, transportation costs), changes in household dynamics and family roles, and challenges navigating healthcare. In particular, caregivers reported strains managing work, family responsibilities, and caregiving tasks with limited resources. Ongoing analyses are examining differences between caregivers and patients and men and women. Male patients in particular expressed despair over the inability to work and the impact this had on their self-identity and perceived burden to others. Conclusion: Participants emphasized the important role of family and religion as a way of coping with the cancer diagnosis and related challenges. Stress associated with economic challenges and changes in family roles was prevalent and appeared to contribute to depression and anxiety. In conclusion, study findings highlight key sources of support and strain among Latino patient-caregiver dyads that can inform culturally relevant and equity-based cancer-related interventions. Citation Format: Larkin L. Strong, Josheili Llavona-Ortiz, Hilary Ma, Maria E. Fernandez, Elizabeth Dominguez, Rosangela Silva, Jaquelin Hernandez, Kathrin Milbury. Sources of support and strain in Latino patients with advanced cancer and their family caregivers [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr B158.