Adrenocorticotropin (ACTH) producing macroadenomas and pituitary apoplexy are unusual in Cushing's disease. A 20-year-old man who had been diagnosed Cushing's disease 2 months ago, presented with sudden headache, nausea, and vomiting. His serum cortisol level was 0.4 mu g/dl and ACTH level was 23.9 pg/ml. Magnetic resonance imaging of the pituitary gland disclosed a hemorrhage in the pituitary macroadenoma (22 x 19 mm). He was treated with IV methylprednisolone immediately and then the symptoms were relieved within the first day of the treatment. The hemorrhagic lesion was resected by transsphenoidal surgery successfully. Impaired secretion of pituitary hormones may be seen after the pituitary apoplexy. We communicate a case with pituitary apoplexy of an ACTH secreting pituitary macroadenoma, causing acute glucocorticoid insufficiency.