Pharmacological manipulation of the sympathetic tone has led to the synthesis of novel compounds to control stress-induced hemodynamic disorders. The use of alpha(2)-adrenoceptor agonists is particularly interesting in this regard, since these agents decrease sympathetic activity by reducing norepinephrine release from nerve terminals. Dexmedetomidine is a potent, highly selective alpha(2)-adrenoceptor agonist. Its use is associated with a decrease in heart rate and blood pressure both in animals and humans. Several lines of evidence suggest that this compound increases perioperative cardiovascular stability and reduces the incidence of ischemic episodes in patients with coronary artery disease. In addition to its cardiovascular properties, dexmedetomidine possesses anxiolytic, hypnotic/sedative, anesthetic-sparing and analgesic actions and is devoid of significant respiratory depressant effects. Targeted mutations of the alpha(2) receptor site indicate that the alpha(2A) subtype is primarily involved in its sedative and anesthetic-sparing effects. Because of these properties, dexmedetomidine may be particularly useful during the perioperative period, as well as for sedation of patients in critical care settings.