Our ability, as leaders in public health scholarship and practice, to achieve and measure progress in addressing racial/ethnic disparities in health status and health care is severely constrained by low levels of participation of racial/ethnic minority populations in health-related research. Confining our review to those minority groups federally defined as underrepresented (African Americans/blacks, Latinos/Hispanics, and Native Americans/American Indians), we identified 95 studies published between January 1999 and April 2005 describing methods of increasing minority enrollment and retention in research studies, more than three times the average annual output of scholarly work in this area during the prior 15-year period. Ten themes emerged from the 75 studies that were primarily descriptive. The remaining 20 studies, which directly analyzed the efficacy or effectiveness of recruitment/retention strategies, were examined in detail and provided useful insights related to four of the ten factors: sampling approach/identification of targeted participants, community involvement/nature and timing of contact with prospective participants, incentives and logistical issues, and cultural adaptations. We then characterized the current state of this literature, discussing implications for future research needs and directions.