This quality improvement project examines the relationship between racial segregation in the Stanford Cancer Institute’s (SCI) catchment area and racial disparities in clinical trial accrual using Geographic Information System (GIS) analysis. It also briefly reviews strategies other cancer centers have used to address the effect of segregation on minority patient accrual in their catchment area. 215 studies in the gastrointestinal oncology clinic trials department at the SCI between 2012 –2020 were reviewed to collect data on race, ethnicity, and zip code of all available trial patients. These variables were plotted in the SCI’s catchment area using ArcGIS Online. A total of 848 patients were analyzed. The ethnicities of our trial patients were 61% White (n=514), 25% Asian/Pacific Islander (n=210), 13% Latinx (n=107), 2% Black (n=14), and <1% American Indian (n=3). 79% of Black patients were in non-interventional trials, and GIS analysis showed that 63% (7/11) of Black patients in the Bay Area resided in the East Bay (Contra Costa and Alameda County) – these areas were also associated with high rates of poverty and low access to personal transportation. This analysis showed racial disparities in clinical trial accrual at an NCI CCC and demonstrated how racial segregation has contributed to this disparity using GIS. While the analysis is limited due to a lack of descriptive variables in our database, supplementary data from the U.S. Census demonstrated a positive correlation between racial segregation and economic conditions that preclude minority patient enrollment – higher poverty rates and lack of personal transportation.