Hypothalamic/pituitary and adrenal (HPA) function was assessed in ten patients who received intermittent high-dose prednisolone and cytotoxic chemotherapy for 5-40 months. Standard insulin hypoglycaemia (IHT), thyrotrophin-releasing hormone and tetracosactrin tests were performed 36 hr after the last dose of prednisolone and subsequently 10 days--52 weeks after completion of all chemotherapy. In the first tests there was evidence of impaired hypothalamic-pituitary function judged by peak adrenocorticotrophic hormone (ACTH), growth hormone (GH) and thyrotrophin (TSH) responses, and corresponding plasma corticosteroid responses were sub-normal in five patients. In the final IHTs, seven patients had persistently subnormal ACTH responses but all the corresponding plasma corticosteroid responses returned to normal. Mean peak corticosteroid responses to insulin and tetracosactrin and peak GH responses were significantly greater than in the first tests. Such chemotherapy regimens may have prolonged effects on hypothalamic/pituitary function but the demonstration of normal corticosteroid responses to hypoglycaemia and tetracosactrin indicates that these patients' stress responses will be normal as early as 10 days after treatment is stopped.