This paper discusses the early implementation of the Mental Capacity Act 2005 in health and social care in England. The author examines the research evidence to date, particularly monitoring data from the Department of Health, in order to review the progress made in implementation. The extent to which the Act is achieving its overall aim of facilitating decision-making by people lacking capacity is discussed, focusing on people with dementia. The author concludes that the initial implementation of the Act (and the related Deprivation of Liberty Safeguards) has had only limited effectiveness in facilitating decision-making by people lacking capacity, promoting their best interests and protecting their liberty. Future implementation needs to ensure that the rights of people lacking capacity, particularly people with dementia, are taken more seriously in health and social care and are better protected.