The Guardianship and Administration Act 1993 (SA) enables SACAT to appoint the Public Advocate as a guardian of last resort [s 29]. The Act uses the term guardianship as a last resort, expecting that an application to SACAT will only become necessary when a satisfactory outcome cannot be arranged informally.

The Public Advocate has a role in encouraging alternatives to formal guardianship.

As a guardian, the Public Advocate can make a number of important life decisions for an individual with a mental incapacity. This power will not allow the Public Advocate to give consent to certain treatments, which still require the authority of SACAT (for example, sterilisation and termination of pregnancy).