OBJECTIVES:  In France, the cost of an osteoarthritic patient has not been estimated for several years.The aim of the study was to evaluate the annual cost of the treatment given to osteoarthritic patients by GP. METHODS: The cohort was made up of patients who were diagnosed with osteoarthritis between April 2009 and March 2010 (IMS Disease Analyzer database) The cost includes all medical cost to the patients in the cohort, and colligated in the Disease Analyzer database (all consultations with GPs and all resulting drug prescriptions). The evaluated cost is therefore the annual cost of treatment given to an osteoarthritic patient. RESULTS: A total of 18,976 patients suffering from osteoarthritis were followed. For these patients, who had an average age of 66, all consultations with GPs as well as all resulting drug prescriptions were valued both in terms of societal cost and cost to health insurance.   The average annual cost of disease management by a GP of a patient suffering from osteoarthritis is therefore valued at €755 societal cost, of which around 60% (€447) is paid by health insurance. The annual cost of treatment by a GP of a patient suffering from hip osteoarthritis is significantly lower at the societal level (€715) than at the health insurance level (€425) compared to patients suffering from osteoarthritis in the knee or elsewhere, despite their higher age. CONCLUSIONS: No literary data evaluating the cost of an osteoarthritic patient currently exists. The closest data is that produced by a COART® France study (Le Pen and coll, Revue du rhumatisme, December 2005). The prevalence of osteoarthritis has been estimated at around 4 million sufferers, even though this figure may be conservative, we can estimate that the cost of osteoarthritis treatment is around 3 billion euros. We are sure that further data will be added to existing ones.