OBJECTIVE: Research that seeks to enroll noncompetent patients with Alzheimer’s disease without presenting any potential benefit to participants is the source of substantial ethical controversy. The authors used hypothetical Alzheimer’s disease studies that included either a blood draw or a blood draw and lumbar puncture to explore older persons’ attitudes on this question. METHOD: Face-to-face interviews were conducted with 538 persons age 65 and older. Questions explored participants’ understanding of research concepts, their views on enrolling persons with Alzheimer’s disease in research, and their preferences regarding having a proxy decision maker, granting advance consent, and granting their proxy leeway to override the participant’s decision. Additional questions assessed altruism, trust, value for research, and perceptions of Alzheimer’s disease. RESULTS: The majority (83%) were willing to grant advance consent to a blood draw study, and nearly half (48%) to a blood draw plus lumbar puncture study. Most (96%) were willing to identify a proxy for research decision making, and most were willing to grant their proxy leeway over their advance consent: 81% for the blood draw study and 70% for the blood draw plus lumbar puncture study. Combining the preferences for advance consent and leeway, the proportion who would permit being enrolled in the blood draw and lumbar puncture studies, respectively, were 92% and 75%. Multivariate models showed that willingness to be enrolled in research was most strongly associated with a favorable attitude toward biomedical research. CONCLUSIONS: Older adults generally support enrolling noncompetent persons with Alzheimer’s disease into research that does not present a benefit to subjects. Willingness to grant their proxy leeway over advance consent and a favorable attitude about biomedical research substantially explain this willingness.