A patient with cerebral dysrhythmia and fever of unexplained origin for 2 years is described. She had elevated and nonsuppressible levels of urinary 17-hydroxycorticosteroids but no clinical features of hypercortisolism. Treatment with valproate sodium corrected all the abnormalities. It is postulated that cerebral dysrhythmia can affect the hypothalamic mechanisms of body temperature and regulation of adrenocorticotropic hormone levels.