INTRODUCTION: Human tissue samples are essential for translational cancer research. However, less than 20% of current biobank and genomic samples were obtained from minority patients, which may lead to biased understanding of cancer biology. The objective of this study was to identify factors associated with patient enrollment in our institution's gastric cancer biobank. METHODS: Patients with suspected or confirmed gastric or gastroesophageal junction cancer undergoing surgical procedures at our institution were invited to enroll in a prospective gastric cancer biobank. We retrospectively reviewed patients who were invited to enroll from 2017 to 2023 at our safety-net and university hospitals. We compared patients who enrolled to those who declined to identify factors that predict enrollment. RESULTS: Hispanic patients had similar odds of enrollment as non-Hispanic White patients (odds ratio (OR): 1.22, 95% confidence interval (CI): 0.54-2.73, P = 0.63). Non-Hispanic minorities (Black/African Americans and Asians) were less likely to enroll when compared to non-Hispanic Whites (OR: 0.41, 95% CI: 0.18-0.95, P = 0.04). Minority patients treated at our safety-net hospital had higher odds of enrollment than those treated at our university hospital (OR: 2.62, 95% CI: 1.11-5.99, P = 0.02). CONCLUSIONS: Efforts to improve diversity in biomedical research cannot consider minority patients as a monolithic cohort. Instead, targeted interventions that address diverse cultural concerns and improve access to enrollment at safety-net centers are requisite.