Advance care planning is becoming an increasingly important feature of health service provision. Although the New Zealand Mental Health Commission has advocated strongly for the provision of advance directives in mental health services, little is known about clinician or service user views on advance directives. The aim of the study was to survey the perspectives of service users and clinicians on the use of psychiatric advance directives. The study used an anonymous online survey to collect data from 110 mental health service users and 175 clinicians. Survey items included existing knowledge, preferred content and potential benefits of advance directives. Descriptive statistics and intergroup comparisons were conducted. Over 90% of service users and clinicians agreed that they support advance directives in mental health. There were similarities in the preferred content of an advance directive across the two groups, particularly regarding the notification of support persons, cultural support and preferred methods of de-escalation. Significant differences in opinion were found regarding the use of coercive measures and the ability of mental health legislation to override advance directives. The results indicate strong support for the use of advance directives within New Zealand mental health services, as well as for further research in the area.