Abnormalities of hypothalamic-pituitary function in patients with anorexia nervosa (AN) have been reported previously. Since atypical responses to thyrotropin-releasing hormone (TRH) and luteinizing-hormone-releasing hormone (LHRH) have been observed in other disease states, hormonal responses to these hypothalamic peptides in 60 otherwise unstressed young women with anorexia nervosa were studied. Sixteen patients demonstrated a growth hormone (GH) response to TRH and 10 showed an increase in GH after LHRH. Five patients had an increase in cortisol after TRH, 2 of whom showed GH response, and 2 patients demonstrated a cortisol response to LHRH, 1 of whom had a GH response. Variable TSH responses to TRH were observed in the study but there was no correlation with the occurrence of GH or cortisol responses. GH responses to TRH and LHRH were typically not seen in the same patients, nor were they predictive of a cortisol response to the same stimulus. These data add to the evidence for an abnormal hypothalamic-pituitary regulation in AN.