Women in general and women of color in particular have been noticeably absent from clinical research, be it phase I pharmacokinetic drug trials or natural history observational studies. This paper examines several questions about the role of women of color in clinical research: Who participates in clinical trials and why? Do women of color face a particular dilemma in deciding to participate? A biologic construct for race and gender research issues is presented. Given the variations of pharmacokinetics and pharmacodynamics that may be race- or gender-related, certain obstacles must be addressed in order to facilitate responsible research. Those obstacles include the history of abuse of vulnerable populations in the name of clinical research, discrimination in medical care, and the lack of understanding of the combined impact of gender, race, ethnicity, and class on behavior and health.