Double staining in situ hybridization studies have shown that angiotensin II (All) type 1 receptors (AT1) in the hypothalamic paraventricular nucleus (PVN) are located primarily in corticotropin releasing hormone (CRH) neurons of the parvicellular subdivision. The purpose of these studies was to investigate the role of All regulating the hypothalamic‐pituitary adrenal (HPA) axis, by correlating AT₁ receptor expression levels in the PVN with the known changes in activity of the HPA axis under different stress paradigms, and manipulation of circulating glucocorticoids. AT₁ receptor mRNA was measured by in situ hybridization using ³⁵S‐labelled cRNA probes and All binding by autoradiography using ¹²⁵I[Sar¹,lle⁸]All in slide mounted hypothalamic sections. AT₁ receptor mRNA levels and All binding in the PVN were reduced by about 20% 18 h after adrenalectomy remaining at these levels up to 6 days after. This effect was prevented by corticosterone administration in the drinking water, or dexamethasone injection (100 mg, s.c., daily). Conversely, dexamethasone injection in intact rats caused a 20% increase in AT₁ receptor mRNA in the PVN. AT₁ receptor mRNA and binding in the PVN increased 4 h after exposure to stress paradigms associated with activation of the HPA axis (immobilization for 1 h, or i.p. injection of 1.5 M NaCl), and remained elevated after repeated daily stress for 14 days. Unexpectedly, two osmotic stress models associated with inhibition of the HPA axis (60 h water deprivation or 12 days of 2% saline intake) also resulted in increased AT₁ receptor mRNA levels and All binding in the parvicellular PVN. In intact rats, the stimulatory effect of acute stress on AT₁ receptor mRNA in the PVN was significantly enhanced by dexamethasone administration (100 μg, s.c., 14 h and 1 h prior to stress), while in adrenalectomized rats, with or without glucocorticoid replacement, stress reduced rather than increased, AT₁ receptor mRNA. Dexamethasone, 100 μg, injected sc within 1 min the beginning of immobilization in adrenalectomized rats, increased AT₁ receptor mRNA in the PVN to levels significantly higher than those after dexamethasone alone, indicating that the stress induced glucocorticoid surge is required for the stimulatory effect of stress on AT₁ receptor mRNA. The data suggest that AT₁ receptor expression in the PVN is under dual control during stress: stress‐activated inhibitory pathways and the stimulatory effect of glucocorticoids. The lack of specificity of the changes in AT₁ receptor expression in the PVN following stressors with opposite effects on ACTH secretion (osmotic and physical‐psychological stress) does not support a role for All as a major determinant of the response of the HPA axis during stress.