Background: Racial and ethnic minorities remain underrepresented in cancer clinical trials (CCTs), limiting the generalizability of findings and equitable access to new therapies. Barriers include limited trial access in diverse communities, low referral rates among medically underserved groups, and lack of awareness or understanding of CCTs. Educational interventions may help address these gaps by improving knowledge and engagement among disparity populations. Objective: Evaluate patient knowledge and beliefs of CCTs after an education intervention at an NCI-designated cancer center. Methods: Patients being treated for any type of cancer were invited (by mailer and posted pamphlets) to participate in a Clinical Trial Social Determinants Survey to characterize their social determinants of health and preferences for clinical trials education. A secondary validated instrument (CHEKS) evaluated patients' knowledge and beliefs about CCTs, before and after exposure to educational stimuli (written and video) detailing the purpose and characteristics of CCTs. Results: A total of 51 cancer patients observed the educational stimuli and completed pre and post surveys. The mean score for positive ‘ knowledge and beliefs' (out of 100) increased from 86.1 pre-intervention to 90.9 post-intervention. The sample was 60.8% female and 39.2% male. One third (33%) reported prior enrollment in a CCT; 47.1% reported annual household income <$75K and 51% reported >$75K; 78% reported education as some college or beyond and 21.6% reported a high school degree or lower; and 62% reported being in a domestic partnership and 37.3% were single. Because 65% of patients were White, and other groups were represented in small numbers, no results by race/ethnicity are reported. For every subgroup (male/female, education low/high, income low/high, previous CT yes/no, coupled yes/no), the educational intervention showed a positive effect, meaning the knowledge score increased post stimuli. Males' knowledge (mean) score increased +5.75 points, while females increased +4.2; married or coupled patients' score increased significantly (+6.59) while single persons had the lowest increase of all subgroups (+1.79). The highest increase in knowledge scores was the high-income group (+6.8), and the low-income group increase was +2.83; high school graduate or less increased +4.09, some college and beyond increased +5; for those who have previously enrolled in a clinical trial the score increased +4.59, and those with no clinical trial experience increased +4.91. Conclusions: Specific and high quality CCT educational material that explains the purpose and phases of CCTs, the need for diverse populations, safety protocols, costs, and patient rights can impact patients' views and understanding of CCTs. By reducing the knowledge barrier, we hope to improve enrollment of underrepresented groups in CCTs.