Since the mid-1960s quality assurance in clinical chemistry has progressed from a need to define and improve precision and accuracy in analytical test procedures to an all-embracing process of assuring that the whole process of pre-analytical, analytical and post-analytical phases of handling patient samples is managed effectively and efficiently. Automated and computer-controlled equipment has reduced many of the analytical errors, in particular in imprecision, that were present in manual analysis. New management techniques have been developed to control the quality and appropriateness of results. Developments in internal quality control and external quality assessment procedures have enabled laboratories to continually improve the quality of assays. Laboratory accreditation and external quality assessment scheme accreditation have ensured that peer review and peer pressure have been applied to both laboratory and external quality assessment scheme performance. As the NHS reviews its priorities and places more emphasis on primary care provider demands, hospital laboratories will of necessity assist with near patient testing outside the laboratory. This will provide new challenges to the quality of the service provided.