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A 67-year-old woman with previously untreated essential thrombocythemia developed bilateral adrenal hemorrhage. She had no known vascular risk factors including smoking, diabetes mellitus, hypertension, and hypercholesterolemia. Her platelet count was 921×109/l. She received preemptive steroid therapy to prevent the occurrence of adrenal crisis, but 5 weeks later the replacement therapy was discontinued because the patient fully recovered with a normal adrenocorticotropic hormone stimulation test. Thereafter, she remained well for more than 4 years with a platelet count ranging from 600 to 800×109/l. Although adrenal hemorrhage is very rare, it can occur as a hemorrhagic complication of essential thrombocythemia.