OBJECTIVES: To review the three national bodies responsible for health technology assessment in the UK: the National Institute for Health and Clinical Excellence (NICE), the Scottish Medicines Consortium (SMC) and the All Wales Medicines Strategy Group (AWMSG); to judge their fitness for purpose; and to assess the value of a multi-layered system. METHODS: The working of the organisations was classified under four headings: objectives and scope; assessment of technologies; the decision process; implementation. The main source of information was the documentation produced by these bodies on their rules, processes and decisions. The health economics and health policy literature was reviewed for commentaries and case studies of particular decisions. Where decisions had been made by different bodies on the same technology those were reviewed for consistency. Parallels were drawn with methods of regulating market access in other European countries. RESULTS: NICE procedures were the most thorough but could not be applied early or to all technologies because of their resource- intensive nature. Methodological expectations for company submissions were similar between organisations, but the degree of independent review varied with the annual number of technologies assessed. In most cases, NICE and SMC decisions on the same drug were consistent. SMC most resembled equivalent systems in other European countries by evaluating drugs at launch. AWMSG was most concerned with budget impact. CONCLUSIONS: Most differences between the organisations could be explained by their differing objectives, scope of activities and timing of their intervention. The SMC was more concerned with timely and comprehensive coverage of all drugs, reflecting its closer links to NHS. NICE was only beginning to address implementation. Properly co-ordinated, the sequence of evaluations could follow a logical development of evidence quality over time, with minimal redundant work on company submissions. Without such co-ordination a waste of valuable time and resources is likely.