The renal community is faced with an ever increasing number of patients reaching end-stage renal failure. Clinical studies have provided clear evidence that angiotensin-converting enzyme (ACE) inhibitors, and probably also AT<sub>1</sub> receptor antagonists, at least in patients suffering from type 2 diabetes, slow disease progression to end-stage renal failure. This protective effect of drugs interfering with the renin-angiotensin system (RAS) are in part independent of reduction in systemic blood pressure, but involve normalization of glomerular hyperperfusion and hyperfiltration, restoration of altered glomerular barrier function, and reduction of stimulated tubular fluid reabsorption. Angiotensin II (ANG II) has emerged in the last decade as a multifunctional cytokine exhibiting many non-hemodynamic properties such as acting as a growth factor and profibrogenic cytokine, and even having proinflammatory properties. This review tries to bridge the classical hemodynamic actions of ANG II in the kidney with the more recently characterized effects of this vasopeptide. Finally, clinical implications are suggested based on data from clinical studies. A thorough understanding of the RAS is important to recognize the potential of nephroprotective strategies through inhibition of its components.