Abstract Germline genetic testing for cancer risk offers opportunities for decision-making about screening and clinical risk management for individuals and their family members. Despite increasing availability of cancer genetic testing, Black individuals are still much less likely to receive or engage with testing compared to non-Hispanic white individuals. We sought to identify individual level factors influencing knowledge about and attitudes toward cancer genetic testing among Black women with and without breast cancer. Participants included 925 women from the Black Women’s Health Study who had previously provided a biospecimen for research and were invited to have their cancer genetic research findings confirmed via a CLIA-certified laboratory and learn their results as part of a randomized controlled trial. Prior to confirmation testing, all women completed a baseline questionnaire about personal and family history of cancer; prior genetic testing for hereditary cancer; and knowledge, attitudes, and confidence in one’s ability to use genetic information (genetics self-efficacy). We used linear regression to evaluate individual-level factors influencing cancer genetics knowledge, attitudes, and self-efficacy. Overall, mean knowledge score was 12.3 out of 16 (SD, 2.5); there were no differences in knowledge score between women who had a personal history of breast cancer and those who did not. While the majority of women answered most questions correctly, 20-30% of women were unable to correctly answer questions about validity of test results, clinical implications of a variant of uncertain significance, and legal protections against health insurance discrimination. Younger age, higher educational attainment, being married, and having had prior genetic testing were statistically significant predictors of higher total knowledge score. There were no differences in mean knowledge scores by first degree family history of breast cancer or personal history of breast or other cancer. Predictors of favorable attitudes and genetics self-efficacy included younger age, higher educational attainment, and being married. Women with a personal history of breast cancer had somewhat more favorable attitudes toward genetic testing compared to those with no prior history of breast cancer. In multivariable adjusted models, higher total knowledge was associated with more favorable attitudes and higher self-efficacy. In this cohort of highly educated Black women, overall cancer genetics knowledge was relatively high; however, evaluation of individual knowledge questions revealed opportunities for improvement in specific areas. Older women, those with lower educational attainment, and women who are not married or living as married may benefit from more targeted education about genetic cancer testing. Further, despite the role genetic testing currently plays in guiding cancer treatment, Black women who had breast cancer did not have higher knowledge scores than those without breast cancer and therefore may also benefit from targeted education. Citation Format: Kimberly A. Bertrand, Michelle Trevino-Talbot, Maggie Rudderman, Maureen Flynn, Howard J. Cabral, Julie R. Palmer, Catharine Wang. Knowledge, attitudes, and self-efficacy toward cancer genetic testing among Black women with and without breast cancer [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 B101.