Acquired amegakaryocytic thrombocytopenic purpura (AATP) is an uncommon disorder with thrombocytopenia and selectively suppressed megakaryopoiesis, often mistaken as immune thrombocytopenic purpura (ITP). It usually does not respond to steroids, and bone marrow examination shows complete absence of megakaryocytes. The treatment and prognosis of AATP vary greatly from ITP; therefore, it is important to diagnose and treat this condition early, as it can progress rapidly to complete bone marrow failure. In this case report, we report a patient with AATP responded well to cyclosporine therapy.