BACKGROUND: African Americans are thought to be more distrustful of clinical research compared to elderly whites, but it is unknown whether specific types of distrust in clinical research, such as interpersonal or societal distrust, vary according to race. The primary objective was to identify racial differences in interpersonal or societal distrust in clinical research among African Americans and whites. METHODS: Seven hundred seventy-six older African Americans and whites were surveyed about their interpersonal and societal distrust using a 7-item index of distrust in clinical research. We combined the 2 societal distrust items into a societal distrust subscale. We also assessed trust in primary care physicians, access to care, health/functional status, previous exposure to clinical research, awareness of the Tuskegee Syphilis Study, perceived discrimination in health care, and sociodemographic characteristics. RESULTS: High societal distrust was more common among African Americans compared to whites (21% vs 7% in the top quartile of the societal distrust, p < .0001), but there were no racial differences in responses to the individual interpersonal distrust index items. In sequentially built multivariable analyses, the relationship between African American race and societal distrust (odds ratio, 2.2; 95% CI, 1.2-3.7) was not completely explained by other factors such as trust in one's physician, previous discrimination, or awareness of the Tuskegee Syphilis Study. CONCLUSIONS: Racial differences according to the type of distrust in clinical research may warrant assessing specific types of distrust separately among racially diverse populations in future studies.