OBJECTIVES: The European Society of Cardiology consensus treatment guidelines in 2002 support use of clopidogrel in many ACS patients for secondary prevention of cardiac events. This study is to examine clopidogrel patterns of use in acute coronary syndrome (ACS) patients in Germany. METHODS: The data source was the IMS Health, Disease Analyzer Mediplus-German database, containing approximately 4.2 million de-identified patient records from approximately 1000 participating practices. The analysis period was January 1, 2001-September 1, 2004. The index ACS event was identified using ICD-10 codes for unstable angina or acute myocardial infarction. Patients were included if they had ≥ 3 months of data before and 6 months after an index ACS event and ≥1 prescription for clopidogrel after the event. RESULTS: Of the 28,688 patients included in the ACS cohort, 748 had at least one clopidogrel prescription (2.6%) and met inclusion criteria. Mean age was 67.5 years; 68% were male. The mean number of recorded comorbidities was 7.4. High cholesterol, hypertension, angina, ischemic heart disease, and diabetes were most common. The recorded mean length of clopidogrel therapy was 41 days. 74% of patients stopped therapy, defined as not on clopidogrel 28-days prior to end of follow-up. A gap in therapy, defined as late refills >14 days apart, was seen in 89%. Concomitant cardiovascular drug therapies included: calcium channel blocker (20.3%), beta-blocker (69.1%) and statin (64.7%). CONCLUSION: This descriptive study suggests clopidogrel is underutilized in ACS patients and long-term adherence to therapy was poor as demonstrated by stoppages or gaps in therapy.