Article 12 of the UN Convention on the Rights of Persons with Disabilities, particularly as interpreted in the Committee on the Rights of Persons with Disabilities General Comment No. 1, presents a significant challenge to all jurisdictions that equate interventions permitted under their mental health and incapacity laws with mental capacity. This is most notable in terms of the General Comment’s requirement that substitute decision-making regimes must be abolished. Notwithstanding this, it also offers the opportunity to revisit conceptions about the exercise of legal capacity and how this might be better supported and extended through supported decision-making. This article will offer some preliminary observations on this using Scottish mental health and incapacity legislation as an illustration although this may also have relevance to other jurisdictions.