OBJECTIVES: Atherothrombosis is the leading cause of death worldwide which creates a huge economic burden. The REACH Registry is an international prospective registry with 67,888 patients from 44 countries, at risk of atherothrombotic events due to coronary artery (CAD), cerebrovascular (CVD) and/or peripheral arterial disease (PAD), or the presence of =3 atherothrombotic risk factors. METHODS: We examined medication (MED) use and estimated annual MED costs (€) in 5594, 2516, and 618 patients from Germany (GE), Spain (SP) and the UK, respectively, using baseline data from REACH. Classes of drugs examined included antiplatelet agents, oral anticoagulants, NSAIDS, lipid lowering agents, antihypertension agents, nitrates or other anti-angina agents, and peripheral arterial claudication medications. Country-specific unit costs were obtained for the 3-4 most commonly prescribed drugs in each MED category, and a weighted average of MED-specific costs, by market share, was applied to annualized utilization rates. RESULTS: Within each country, average # MEDs increased with # diseased vascular sites (GE:3.6/4.3/5.0;SP:3.4/3.8/4.1;UK:3.6/4.2/4.7, for 0/1/2-3 vascular sites, respectively). Patients with CAD only reported greater # MEDs (GE:4.7;SP:4.5;UK:4.4) than patients with CVD only (GE:3.7;SP:3.0;UK:3.3) or PAD only (GE:3.5;SP:2.5;UK:3.1). Greater than two thirds reported taking at least 1 lipid lowering agent (GE:74%;SP:68%;UK:85%), and >85% reported taking at least 1 antihypertensive agent (GE:94%;SP:86%;UK:88%). Average costs were higher for GE compared to SP and UK due to higher unit costs for nearly all MEDs. Lipid lowering and antihypertensive agents accounted for >50% of MED costs (GE:70%;SP:54%;UK76%). Costs tended to increase with # diseased vascular sites (GE:€770/€993/€1164;SP:€492/€586/€710;UK:€546/€553/€668, for 0/1/2-3 vascular sites, respectively). CONCLUSION: In this population of patients with either stable vascular disease or multiple atherothrombotic risk factors, use of multiple medications was common. Medication use and associated costs tend to increase with the number of diseased vascular sites, and contribute to the economic burden of atherothrombosis.