SYNOPSIS Chlorpromazine, given intravenously, is a useful agent in the treatment of acute migraine headaches. Patients with more serious conditions, however, may also respond to this medication. In this paper we report two patients who were initially diagnosed as having migraine headaches and treated with chlorpromazine. Both experienced temporary pain relief and it was only after repeated presentations to the emergency department that their conditions‐a subarachnoid hemorrhage and a subdural hematoma‐were accurately diagnosed. Because of this, caution must be exercised before re‐treating within a short period of time, a patient with recurrent headache. Strong consideration must be given to an alternate diagnosis and such a diagnosis should be actively sought should there be any suspicion of a non‐migrainous cause for headache. It is only by doing so that we may avoid missing more serious and life‐threatening conditions such as those with which our patients presented.