BACKGROUNDRace-related health disparities have been well documented in the United States. In some settings, Black patients have better outcomes in hospitals that serve high proportions of Black patients. We hypothesized that Black trauma patients would have lower mortality in high Black-serving (H-BS) hospitals.METHODSWe identified all adult patients with Black or White race and with an Injury Severity Score of ≥4 from the 2017 National Inpatient Sample. We collected hospital identifier, mechanism, age, sex, comorbidities, urban-rural location, insurance, zip code income quartile, and injury severity calculated from International Classification of Diseases, Tenth Revision, codes. We used a previously published method to group hospitals by proportion of Black patients served: HB-S (top 5%), medium Black serving (5–25%), and low Black serving (L-BS; bottom 75%). Adjusted logistic regression using an interaction variable between race and hospital service rank (reference: White patients in H-BS) was used to identify factors associated with mortality.RESULTSWe analyzed 184,080 trauma patients (median age, 72 years [interquartile range, 55–84 years]; Injury Severity Score, 9 [4–10]), of whom 11.7% were Black. Overall mortality was 4%. Of 2,376 hospitals, 126 (5.3%) were H-BS and 469 (19.7%) were medium Black serving. Furthermore, 29.8% of Black and 3.6% of White patients were treated at H-BS hospitals, while 71.7% of White and 23.6% of Black patients were treated at L-BS hospitals (p < 0.001). Black patients had the lowest mortality at H-BS hospitals (odds ratio [OR], 0.76 [0.64–0.92]) and the highest mortality (OR, 1.43 [1.13–1.80]) at L-BS hospitals. White patients had the lowest mortality at L-BS hospitals (OR, 0.76 [0.64–0.92]).CONCLUSIONAfter adjusting for patient and hospital factors, disparities exist such that Black and White patients have the best outcomes in hospitals that treat those patients most frequently, suggesting potential for racial bias at the institutional level. Further efforts must be made to promote equitable treatment at all hospitals and reduce these disparities.LEVEL OF EVIDENCEPrognostic and Epidemiologic; Level IV.