OBJECTIVES: To evaluate current practice, characteristics of treated population, utilization of resources and direct medical costs related to anticoagulation treatment in 6 indications in Poland. METHODS: The study consisted of 3 parts: cross-sectional study (performed in hospitals and open care), retrospective chart review and experts opinion-based study. The study was carried out between December 20, 2010 and March 15, 2011. Patients data on anticoagulation therapy or with atrial fibrillation or immobilized were included in cross-sectional part (2021 hospitalized patients and 4175 monitored in outpatient treatment). Documentation of 1752 patients treated for stroke, myocardial infraction, coronary artery disease, deep vein thrombosis, pulmonary embolism or atrial fibrillation or undergoing surgery (e.g. hip or knee replacement) was included in retrospective chart review. A total of 546 face-to-face interviews with physicians of different specializations (orthopedists, general and vascular surgeons, cardiologists, neurologists, general practitioners and rehabilitation therapists) were conducted in opinion-based study. Projection of treated population was made in order to generalize the results to the whole country. RESULTS: About 150,000 prescriptions for anticoagulants were made within 2 weeks of study. Approximately 36,000 patients daily were treated with anticoagulants in hospitals. The main reason for administrating anticoagulants in outpatient treatment was primary stroke prevention in patients with atrial fibrillation (28%), secondary prevention of venous thromboembolism (18%) and secondary stroke prevention in atrial fibrillation (14%). During hospitalization anticoagulants were administered mainly as a prevention of venous thromboembolism in patients who underwent a surgery (33%), or were immobilized due to other reasons (17%). Vitamin K antagonists accounted for 65% of market in outpatient practice, while low-molecular-weight heparins (LMWH) constituted 77% in inpatient treatment. CONCLUSIONS: Administration of anticoagulants in inpatient treatment is usually surgery-related, while in outpatient treatment the most common reason is stroke prevention. Oral anticoagulants are usually administrated in outpatient treatment, while LMWHs are most commonly used in hospitals.