In all the case reports it may be noted that the treatment of this severe disorder has been entirely nonspecific and has been directed primarily toward the correction and amelioration of the distressing symptoms of the disease, particularly pain and fluid imbalance.This report concerns itself with a case of acute intermittent porphyria of the "mixed" variety, combining the features of the light-sensitive and the acute type. It is noteworthy, as it presents the first recorded case in which dramatically successful therapy was accomplished with adrenocortical hormone.A 39-year-old Englishwoman was first observed by us on Sept. 21, 1952, with a three-day history of rapidly progressing nausea, vomiting, inability to tolerate food or fluids, obstipation, and severe epigastric pain radiating to the back and to both flanks. Associated with these