BACKGROUND:Clopidogrel is widely used in cardiovascular prevention. However, the prescription of clopidogrel in clinical practice does not match the recommendations concerning its indication and treatment duration. OBJECTIVE:To assess the appropriateness of clopidogrel prescription according to the accepted indications. METHODS:We undertook a retrospective observational analytical audit of the electronic clinical records in the region of Valencia, Spain (5 million inhabitants), selecting those patients on treatment with clopidogrel between 2007 and 2010. The primary outcome measure was the duration of the treatment. RESULTS:A total of 45721 patients started clopidogrel treatment during the study period. Treatment was for cardiologic disorders (CD) in 56.85% of the patients, neurologic disorders (ND) in 37.06% and peripheral arterial disease in 6.08%. Treatment duration was longer than that expected from clinical recommendations in 38.8% of the CD patients and 87.8% of the ND patients. The estimated avoidable cost ranged from 2 to 4.4 million Euros per year, according to whether a cheaper generic clopidogrel or a more expensive version was considered. CONCLUSIONS:Almost 40% of the cardiologic patients and 90% of the neurologic patients received excess treatment. Adjustment of treatment duration to international recommendations would result in savings of between 80.1 and 176.3 Euros per year and per patient treated.