This article discusses the issues surrounding whether patients have the capacity to consent, which will depend on their age and understanding. The provisions of the Mental Capacity Act 2005 are discussed, including how to assess whether patients are able to make their own decisions, and how to deal with them if they are not. The article also covers the differences between the consent and refusal of a child to treatment. It also discusses the issues surrounding whether sufficient information has been given to the patient and the consequences of not doing so.