OBJECTIVES: 1) Compare the quality of primary care in France to that in the UK through a comparison of the avoidable hospitalization rates in both countries, and 2) Shed light on the determinants of the quality of primary care through a comparison of practices between the two countries for three Avoidable Hospital Conditions (AHC). METHODS: We counted the total number of hospitalizations for 12 AHCs defined by Weissman et al. Patient hospitalization records were drawn from the PMSI database for France (2006) and the HES database for England (April 2006- May 2007). First, we calculated the age-adjusted hospital admission rates for adults 18 years and older, based on the United Nations Standard Population. Second, we adjusted the avoidable hospitalization rates to the prevalence of corresponding conditions. That was possible for three AHCs for which prevalence was documented: asthma, hypertension, and diabetes. To compare primary care practices, we tracked and followed, patients treated for pneumonia, pyelonephritis and asthma in the IMS DiseaseAnalyser® database based on panels of general practitioners in France and the UK. RESULTS: The age-adjusted and the prevalence-adjusted avoidable hospitalization rates were simultaneously higher by 24% and 67% for the UK compared to France. When comparing the primary care practice in both countries for the same pathologies, we found that French and British GPs prescribe similarly according to the therapeutic recommendations. The only difference we could observe was in the access to the primary care providers where the French health system organization makes it a lot easier to consult a physician and get appropriate primary care.    CONCLUSIONS: According to the Avoidable Hospitalization indicator, the quality of primary care is better in France than in the UK. It allowed avoiding 18.5% of the hospitalizations for the 12 AHCs in 2006 which represents almost 117,000 hospitalizations. Could a higher quality of primary care reduce hospital expenditures?