A 35 year old woman suffering from ACTH and prolactin (Prl) deficiency is described. Her symptoms of adrenal insufficiency appeared gradually after her first pregnancy in 1970; however, she conceived twice more and delivered healthy babies in 1972 and 1974, which she could not breast feed due to lack of milk. During an episode of pneumonia in 1977 she suffered acute adrenal insufficiency, after which she began treatment with hydrocortisone. Her pituitary reserve for TSH, GH, LH and FSH was normal, but her ACTH and Prl levels were undectable and did not respond to acute iv challenges of corticotrophin-releasing factor (CRF) and TRH, respectively. Autoantibodies, including antilactotroph titres, were negative, except for a positive pituitary immunofluorescence to ACTH. There was also no ACTH stimulation to a prolonged infusion of CRF followed by an acute iv bolus. These results, together with the gradual onset of symptoms which worsened after each pregnancy, suggest a possible autoimmune aetiology of her pituitary ACTH and Prl deficiencies.