Abstract: This paper discusses the utility of Consumer Notes Clinical Indicators (CNCI) as a means to monitor mental health nursing clinical practice against the Australian and New Zealand College of Mental Health Nurses' (ANZCMHN) Standards of Practice for mental health nursing in New Zealand. CNCI are statements describing pivotal mental health nursing behaviours for which evidence can be found in the nurses' case notes. This paper presents 25 valid and reliable CNCI that can be used to monitor mental health nursing practice against the ANZCMHN's Standards of Practice for mental health nursing in New Zealand. The bicultural clinical indicators were generated in focus groups of Maori and non-Maori mental health nurses, prioritised in a three-round reactive Delphi survey of expert mental health nurses and consumers, pilot tested, and applied in a national field study. This paper reports the development and validation of the CNCI, for which achievement is assessed by an audit of the nursing documentation in consumer case notes. The CNCI were tested in a national field study of 327 sets of consumer case notes at 11 district health board sites. The results of the national field study show wide variation in occurrence of individual indicators, particularly in the areas of informed consent, information about legal rights, and provision of culturally safe and recovery-focused care. The authors discuss the implications of using the CNCI to assess the professional accountability of mental health nurses to provide quality care. Recommendations are made regarding the application of the clinical indicators and future research required, determining appropriate benchmarks for quality practice. The CNCI could be adapted for application in other mental health nursing and other mental health professional clinical settings.