Hypertension after brain injury requires comprehensive evaluation and management. Focal brain injury to centers of blood pressure regulation, high levels of circulating catecholamines from generalized trauma or intracranial lesions, increased intracranial pressure, pheochromocytomas unmasked after trauma, and occult spinal cord injury with hyperreflexia represent possible causes of hypertension after brain injury. This case of a brain-injured patient who had episodes of hypertension and diaphoresis with catecholamine elevations in plasma and urine, and evidence of hypothalamic-pituitary dysfunction, demonstrates the importance of a thorough neuroendocrine evaluation in brain-injured patients with hypertension. When high levels of catecholamines are found, without further evidence of a pheochromocytoma, treatment with a beta blocker is appropriate.