Our improved understanding of the experience of people with dementia provides a new impetus to address legal and ethical issues. This paper explores emerging issues in relation to awareness in dementia and its impact on legal and ethical matters. The different approaches and principles demonstrated in relation to ethical issues are discussed, with an exploration of the concepts of beneficence, non-maleficence, autonomy, and paternalism. Application of these concepts is discussed in relation to advance directives, capacity, and decision making, participation in research and treatment, including informed consent, and truth telling. The tensions that exist between the imperatives of doing no harm and of maintaining autonomy in addressing legal and ethical issues are highlighted, and attention drawn to the manner in which the attribution of unawareness is used to justify withholding autonomy. The review emphasizes the importance of considering competency and awareness as being multi-faceted, to be understood in the context of social interaction.