To evaluate the racial and ethnic representation of transarterial therapy for hepatocellular carcinoma (HCC) clinical trials in the United States. The ClinicalTrials.gov database was examined to identify all completed studies with transarterial therapies for the management of HCC in the United States and extract information about the observed number of participants for each racial and ethnic group (based on the Office of Management and Budget definitions). The expected number of participants was calculated by multiplying the total number of participants in a trial with the U.S.-population HCC-based proportion for each group. The effects of the study phase, funding source, number of centers involved in the study, and the location of the participating center on racial and ethnic distribution were explored. Seventy-nine relevant studies were identified, of which 27 (34.2%) and 18 (22.8%) reported ethnic and race characteristics, respectively. Most study participants were White (81%, 1,591/1,964) by ethnicity and not Hispanic or Latino (93%, 937/1,008) by race. In terms of the observed-to-expected ratios by race and ethnicity in all trials, White and not Hispanic or Latino participants were overrepresented with a ratio of 1.22 (1.10-1.37) and 1.33 (1.26-1.41), respectively, and all other racial and ethnic groups were underrepresented. The enrollment of African Americans and Asian Americans varied by the study phase, and a higher enrollment of African Americans was noted in the National Institutes of Health-funded and multicenter studies (P < .05). This cross-sectional study demonstrates that in HCC transarterial therapy clinical trials, racial and ethnic minorities were underrepresented and the majority of the studies identified failed to report this demographic information.