Objectives The disclosure of an Alzheimer’s disease diagnosis poses challenges for health care professionals, patients, and their families. Past research has shown that people favour disclosure, but it is uncertain if this situation has changed. Method We used a cross-sectional online survey to explore disclosure preferences in a sample of young adults (n = 229; 66.7% aged 18 − 25 years, 79.5% Australian born). Factors contributing to preferences were also examined (knowledge, experience, close experience, age, relationship to diagnosis recipient). Established measures were used to assess knowledge (the Alzheimer’s Disease Knowledge Test) and preferences (the Reasons for Wanting to Know Questionnaire). Results Most (95%) but not all participants favoured disclosure, whilst recognising as important at least one reason against it. Only age was a significant determinant of preferences (older people were more likely to prefer disclosure). Those against disclosure cited the fear of suicide as a key reason. Conclusion The right to know remains a primary reason for preferring disclosure. Health care professionals should use pre-diagnostic interviewing to discuss overall preference and the underpinning reasons both for and against disclosure. Focus should be on developing a person-centred approach that responds to concerns, with further research to evaluate this approach.