Recent advances in biomarkers may soon make it possible to identify persons at high risk for late-onset Alzheimer’s disease at a presymptomatic stage. Popular demand for testing is increasing despite the lack of cure and effective prevention options and despite uncertainties regarding the predictive value of biomarker tests. This underscores the relevance of the ethical, cultural and social implications of predictive testing and the need to advance the bioethical debate beyond considerations of clinical consequences. Our qualitative study included three groups (...) of affected persons: People with mild neurocognitive disorder, their relatives and family caregivers of people with dementia. We explored their moral motivations regarding predictive, biomarker-based testing and preclinical diagnostics. We interviewed affected individuals in Germany and Israel. Transcripts of 12 focus groups and 12 semistructured interviews were content analysed with a focus on the moral motivations of affected persons in their justification of why they accept or reject predictive testing and early diagnosis. We grouped the underlying aspects of moral motivation into four ethical categories: beneficence as a form of personal utility focusing on well-being, the ties of responsibility linking families and their individual members, the importance of self-determination by later life planning and notions of a good life. In general, cultural parallels among these motives were very obvious. Cultural variation occurred mainly in openness to suicide, scepticism about test validity and emphasis on personal autonomy. The study underscores the importance of counselling for life-planning issues and of informing test candidates about problems with test validity and about the ambiguity of test results. All data relevant to the study are included in the article or uploaded as supplementary information. (shrink)