Abstract Background: Racial disparities in breast cancer outcomes persist and are attributed to multiple factors; however, treatment-related side effects, one of the most frequently implicated reasons for poor quality of life and treatment disruptions have been underexplored as a contributor to the disparity. The purpose of this study was to explore similarities and differences in Black and White women's experiences with breast cancer treatments, with a particular focus on their experiences with side effects. Methods: This was a secondary analysis of qualitative data that were originally collected to understand breast cancer survivor's experiences taking adjuvant endocrine therapy (AET). This analysis focused on discussions about side effects related to multiple treatment modalities, including chemotherapy, radiation, and AET. Women were recruited from healthcare centers and via community organizations in an urban U.S. city. Women were eligible for the study if they identified as Black/African American or White and were taking AET. Participants attended one focus group with women who identified as the same race. Focus groups were conducted between August 2014-August 2015, lasted 90-120 minutes, and were transcribed verbatim. Using an iterative approach, initial open codes were identified by two individuals, compared within and between interviews, and refined to generate themes. Disagreements were resolved via a third reviewer. Results: A total of 21 women attended one of three focus groups (n=16 Black women; n=5 White women). Three overarching themes were identified: Side Effect Recognition, Communication about Side Effects, and Coping with Side Effects. Women's descriptions of their side effects closely mirrored domains of the Functional Assessment of Cancer Therapy Endocrine Therapy scale (e.g., vasomotor symptoms). Black and White women also reported weight changes as a result of adjuvant endocrine therapy (weight gain) and chemotherapy (weight loss). The majority of women in our sample reported at least one side effect; however, reporting ‘no side effects' only occurred among White women. Ratings of provider communication about symptoms were mixed; some women found communication helpful while others reported feeling dismissed. While one woman expressed provider negligence concerning mitigating side effects, another remarked on the accessibility of her provider to answer all her questions. Women discussed various methods to cope with side effects, including exercise and medications to relieve joint and bone pain. Spirituality as a method to cope only emerged in the focus groups with Black women. Conclusion: Black and White women reported relatively similar experiences with treatment-related side effects. Future work is needed to understand why Black women may experience more side effects to treatment. Further, culturally-tailored approaches to address treatment side effects that incorporate spirituality are needed to mitigate side effects, which may ultimately improve treatment adherence, quality of life, and outcomes in Black women. Citation Format: Arnethea L. Sutton, Maria D. Thomson, Alejandra Huratdo-de-Mendoza, Vanessa B. Sheppard. “At some point or another, it has affected all of my five senses.”: A qualitative assessment of treatment-related side effects in Black and White breast cancer survivors [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PO-109.