Key clinical messageAlthough aplastic anemia has not previously been reported as a cause of cardiac tamponade, immunosuppressant medication has been associated with pericardial effusion in the context of hematopoietic stem cell transplantation. We report a case of cardiac tamponade secondary to hemopericardium in a patient with aplastic anemia who was receiving cyclosporine. The patient exhibited no evidence of inflammation, infection, autoimmune disorders, or malignancy affecting the pericardiumKeywords: aplastic anemia, cardiac tamponade, pericardial effusion, hemopericardium, cyclosporin, case report