Medical mistrust is one of the most prominent barriers to organ donation registration for African Americans, who comprise a disproportionate number of individuals on the organ transplant waiting list. To date, medical mistrust related to organ donation has primarily been conceptualized as a fear of premature declaration of death. However, the history of African Americans? relationships with medical institutions suggests that this conceptualization may be too narrow. In the current study, we conducted a secondary analysis of focus group discussions to gain a better understanding of African Americans? medical mistrust regarding organ donation. Results revealed four categories of medical mistrust beliefs: societal distrust, distrust of general institutions, distrust of medical institutions, and organ donation-specific medical mistrust. In addition, medical mistrust beliefs appeared to be the result of personal experiences, interpersonal communication, and exposure to the media. Our results are discussed with an emphasis on the theoretical and practical implications for health practitioners working to increase the rates of organ donation among African Americans.