The clinical correlates of hypothalamic-pituitary-adrenal (HPA) functioning were examined in 29 patients with probable Alzheimer's disease. The 8:00 a.m. postdexamethasone cortisol levels of these patients were highly correlated with higher agitation scores but not with the degree of depressed mood or memory impairment. The possible neural basis for the association between hypercortisolism and behavioral disturbance in Alzheimer's disease warrants further exploration and replication.