SummaryLatter years works have thrown a new light on the relationships between the kidney and the adrenal cortex. Beside the well known actions of the corticosteroids on renal excretion of electrolytes, the hormones of the adrenal cortex and the Na content of the diet modify the granularity of the juxtaglomerular apparatus of Goormaghtigh. They control also the amount of renin present in the kidney. Recent works have allowed to localize the renin in the very neighbourhood of the glomerulus and probably in the juxtaglomerular apparatus.Conversely, the renin seems to play a trophic role on the glomerular layer of the adrenal cortex. In the light of these observations, the pathogenesis of arterial hypertension is briefly discussed.If the renin seems to be responsible of the increase of the blood pressure in the acute phase of hypertension of renal origin, this is no more the case in the chronic state. The role of the adrenal cortex for maintaining the hypertension is discussed : several arguments are yet opposed to the idea that the adrenal cortex and particularly aldosterone, may be responsible of the persistence of high blood pressure.Lastly, the protective role of the normal kidney in nephrogenic hypertension is confirmed by the results of the transplantations realized in man.