Anticoagulant therapy is widely used for prevention and treatment of cardiovascular disease and is frequently prescribed both in primary and secondary care. In comparison to other drugs, the frequency of medication errors is high for anticoagulant therapy. In Denmark, 4,383 adverse events with vitamin K antagonists and 3,234 adverse events with non-vitamin K antagonist oral anticoagulants were reported to the Danish Patient Safety Authority in 2014-2017. In this review, we provide an overview of medication errors and discuss frequent adverse events and pitfalls.