OBJECTIVE: To evaluate the transferability of primary care quality indicators by comparing indicators for common clinical problems developed using the same method in the UK and the USA. METHOD: Quality indicators developed in the USA for a range of common conditions using the RAND-UCLA appropriateness method were applied to 19 common primary care conditions in the UK. The US indicators for the selected conditions were used as a starting point, but the literature reviews were updated and panels of UK primary care practitioners were convened to develop quality indicators applicable to British general practice. RESULTS: Of 174 indicators covering 18 conditions in the US set for which a direct comparison could be made, 98 (56.3%) had indicators in the UK set which were exactly or nearly equivalent. Some of the differences may have related to differences in the process of developing the indicators, but many appeared to relate to differences in clinical practice or norms of professional behaviour in the two countries. There was a small but non-significant relationship between the strength of evidence for an indicator and the probability of it appearing in both sets of indicators. CONCLUSION: There are considerable benefits in using work from other settings in developing measures of quality of care. However, indicators cannot simply be transferred directly between countries without an intermediate process to allow for variation in professional culture or clinical practice.