Quality assessment in mental health services is undergoing change in the United Kingdom following the introduction of market reforms. Traditionally, service quality was monitored by professional practitioners with reference to user satisfaction. This became formalized, and the two main forms of quality assurance currently used are outlined. However, the government is concerned that this may be inadequate for the monitoring of quality standards, specified in contracts between service purchasers and providers, and that existing systems provide an insufficient indication of service outcome. As a consequence, the government financed the development of a new set of health outcome scales. The importance of these scales are discussed.