This preliminary study explored the roles of knowledge, attitudes, and significant others on decisions of older African-American women to enroll in a clinical trial involving estrogen and osteoporosis. Sixteen older African-American women (average age 75 years) participated in three focus groups. Twelve of the women had enrolled in the clinical trial and four, although eligible, refused to enroll. Discussions revealed that knowledge of osteoporosis and estrogen and expectations of personal rewards and group benefits from medical research appear to differentiate the women who participated in the clinical trial from those who refused. The women who participated also perceived the research institution as accessible. In addition, assuring full disclosure of testing procedures and test results eased their apprehensions about participation. However, the women who refused to enroll saw no personal benefit and were unwilling to expose themselves, in part because of their age, to the risks of taking estrogen and the uncertain outcomes of the clinical trial. The study illustrates how focus groups can be used to develop multiple strategies to enable recruitment of older African-American women with different demographic characteristics, levels of knowledge, and attitudes toward a disease and medical research.