The quality management systems of the Departments of Diagnostic Radiology of St George's Hospital, London, and Bristol Royal Infirmary (BRI) have been certified with the British Standard 5750. These were the first clinical departments in the UK to be certified to this internationally recognized quality assurance (QA) standard. Quality is a much used term; in this context it is defined as 'fitness for purpose', and quality assurance is the mechanism by which quality is achieved. The paper describes the features of the quality system which have been implemented at St George's Hospital, and how a management concept for manufacturing industries has been adapted successfully to a National Health Service Department. The paper also demonstrates how the quality system has led to the setting and achieving of departmental objectives.