Cyclic acquired amegakaryocytic thrombocytopenic purpura (AATP) is a rare disorder characterized by periodic fluctuations in the platelet counts due to a defect in the platelet production. We describe a 42-year-old female with cyclic AATP, in whom the cyclic fluctuations in the platelet counts ceased with danazol therapy. The pathogenesis of the disease and the possible mechanisms of danazol action have been reviewed.