The pituitary-thyroid axis, serum prolactin and growth hormone levels were studied in 29 patients within 9 d of onset of acute ischaemic stroke. When compared to a control group of 80-year-old volunteers (n = 33), stroke patients were found to have elevated free thyroxine indices (P = 0.008), after adjustment for age and sex. Seventeen (81%) of the stroke patients showed a paradoxical rise in growth hormone in response to thyrotropin releasing hormone (TRH). In a multiple regression model, disorientation was associated with a low thyrotropin response to TRH (P = 0.02 and P = 0.04; 20 and 60 min after TRH, respectively). Disorientation was also positively correlated with the prolactin response to TRH (P = 0.045 after 60 min). Growth hormone levels were predicted by extensive motor impairment (P = 0.02). In conclusion, changes in pituitary and thyroid hormones were commonly observed after stroke and were closely associated with cognitive and/or motor impairment.