A thirty-eight year-old lady with a history of bilateral adrenalectomy for Cushing's disease seven years previously, presented with sudden onset of severe headache, nausea, vomiting and loss of consciousness. She was somnolent and confused. She had neck stiffness, sixth nerve palsy and mydriasis on the left side. Computerized tomography (CT) and magnetic resonance imaging (MRI) studies revealed a non-homogeneous, grade IV D pituitary mass lesion associated with hemorrhage in the chiasmatic, interhemispheric, cerebellopontine, perimesencephalic cisterns and a hematoma within the frontal lobe. Angiography showed only bilateral elevation of horizontal segments of the anterior cerebral arteries. According to this angiographic evidence, it was presumed that the subarachnoid hemorrhage and the intracerebral hematoma were linked to pituitary adenoma apoplexy. ACTH level was 450 pg/ml. The hemorrhagic lesion with suprasellar extension was totally removed by left pterional craniotomy. Histological examination revealed a necrotic, ACTH-secreting pituitary adenoma. Even though apoplexy is a well known complication of pituitary adenomas, to our knowledge subarachnoid hemorrhage and intracerebral hematoma as a result of pituitary apoplexy in the context of Nelson's syndrome has not previously been reported.