Although primary prevention studies are important tools in helping the healthy elderly stay healthy, recruiting from a community-based cohort of healthy elderly individuals for a primary prevention study involves numerous barriers. To better identify and understand these barriers, we conducted and evaluated a comprehensive recruitment strategy for a primary prevention study testing aspirin in an HMO population. In the recruitment phase, we identified healthy individuals (65 years of age or older) who were members of a large, group-model HMO in Oregon and Washington, and used computerized medical database screening, statistical sampling, health plan mailings, e-mail communication with primary care providers, and the experience of a well-established research clinic in an effort to enroll health elderly in this primary prevention trial. Among a random sample of 47,453 eligible patients over the age of 65, 44% responded to recruitment efforts, but only 3% were enrolled--an overall yield of slightly less than 2%. To evaluate these results, we then conducted focus groups with 225 randomly selected "eligible refusers." We determined that healthy elders were hesitant to give up their choice to use aspirin, unwilling to travel to the research center, and reluctant to risk their tenuous hold on good health to participate in a study of primary prevention. Awareness of these attitudes is an indispensable step toward designing effective recruitment strategies for primary prevention studies involving the healthy elderly.