BACKGROUND: The relevance of early decision making will rise with increasing availability of early detection of Alzheimer's disease (AD) using brain imaging or biomarkers. RESULTS: Five people with mild AD, six relatives and 13 healthcare professionals with experience in the management of AD were interviewed in a qualitative study regarding medical and social decision topics that emerge after early diagnosis of Alzheimer's disease. Medical treatment, assistance in everyday life and legal issues emerged as the main decision topics after an early diagnosis of AD. People with AD mostly got in contact with the health and social care system through the initiative of their spouses. They were usually aware of their illness and most received antidementia drugs and/or behavioural interventions. Following diagnosis people with AD received support by their spouses. Healthcare professionals were aware of the risk of excessive demand on relatives due to supporting their family member with AD. In the opinion of healthcare professionals legal issues should be arranged in time before patients lose their decisional capacity. In addition, people with AD and spouses reported various coping strategies, in particular "carry on as normal" after diagnosis but mostly are reluctant to actively plan for future stages of the disease. CONCLUSIONS: Due to the common desire to "carry on as usual" after a diagnosis of AD, many people with AD and spouses may miss the opportunity to discuss and decide on important medical and social topics. A structured approach e.g. a decision aid might support people with AD and spouses in their decision making process and thereby preserve persons' with AD autonomy before they lose the capacity in decision-making.