 There is little doubt of the necessity for further improvement in the prevention and therapy of end-stage renal disease. Despite the success of ARB in treating diabetic nephropathy, not all patients obtain satisfactory control of blood pressure, albuminuria and decline in renal function. Experimental data have provided us with a rationale for the potential added benefits of ET receptor blockade to the AII inhibition in diabetic renal protection. Considering the nephroprotective effect of bosentan in diabetic rats, clinical studies are warranted to assess whether ET receptor antagonism has additive renoprotective effects on top of AII inhibition. 