The regulation of blood pressure is a complex process, involving several organs. The kidney plays a major role and is involved in the initiation and maintenance of hypertension. Mechanisms involved are: (1) the sympathetic nerveous system, (2) the renin-angiotensin system, (3) the regulation of sodium and water balance, (4) the production of vasoactive substances such as endothelin, adenosine or nitric oxide (NO), and (5) structural alterations such as a reduced number of glomeruli and nephrons. Several therapeutic intervention strategies affecting these mechanisms have already proven to be effective antihypertensive drugs.