Current guidelines are mandatory in the choice of anticoagulant and/or antiplatelet therapy in patients with atrial fibrillation undergoing percutaneous transluminal coronary angioplasty and in patients with coronary artery disease and previous percutaneous transluminal coronary angioplasty that develop atrial fibrillation. However, in the real world there are crossroads with multiple choices, especially taking into account patient’s peculiar characteristics and risk factors, which sometimes are not represented in the guidelines. The reported clinical case focuses on the choice of anticoagulant therapy in a patient with chronic and severe coronary artery disease and new diagnosis of atrial fibrillation who, considering his specifically high coronary thrombotic risk, probably should continue antiplatelet therapy.