We present the case of a 52-year-old man with a 2-month history of dyspnea, bilateral pleural effusion and cardiomegaly of rapid onset. A cardiac ultrasound showed pericardial effusion with infiltration of the infero-lateral cardiac wall, right auricle and aortic arch by a mass of unknown origin. Despite 1% blast cells in the peripheral blood, 2 bone marrow biopsies were negative for malignancy. Flow cytometry analysis of the blood and immunohistochemistry study of the pleural liquid showed a blast population of CD34+, CD33+, CD13+ and HLA-DR+ cells; a percutaneous cardiac biopsy showed CD34+ cells in the pericardium which led to the diagnosis of extramedullary acute myeloid leukemia (AML). The patient was treated with induction chemotherapy allowing remission, but unfortunately died of septic shock of fungal origin. This case illustrates a rare presentation of cardiac extramedullary AML.