The very diverse clinical expressions of pheochromocytoma are dependent upon type of catecholamine secreted and excreted by the tumor. The role of each of the three amines (adrenaline, noradrenaline, dopamine) is reviewed in relation to physiologic regulation of blood pressure: adrenaline and noradrenaline are pressor hormones and act on almost all blood pressure factors. They possess chronotropic and positive inotropic effects by their action on cardiac beta 1 adrenoceptors, a peripheral vasoconstricting action by interaction with vascular alpha 1 receptors and a direct effect on renin production and tubular resorption of sodium. Inversely, dopamine presents as a hypotensive agent, opposing effects of adrenaline and noradrenaline and possessing numerous sites of action: central hypotensive action on cardiovascular integration structures, inhibitory effect on sympathetic ganglionic neurotransmission, action on specific presynaptic receptors at nerve endings, reducing sympathetic vasoconstrictor tone and finally a direct vasodilator effect. Based on these recent physiologic data the role is discussed of hypersecretion of each amine in the cardiovascular expression of pheochromocytoma. Attention should be concentrated on the nature of hormonal hypersecretion of pheochromocytoma, and a determining role given to the type of catecholamine secreted by the tumor and to the relation between the different amines with respect to the blood pressure symptomatology of pheochromocytoma.