In epidemiological studies including serum creatinine or estimates of glomerular filtration rate (GFR), pulse pressure (PP) emerged as significant predictor of cardiovascular risk and major determinant of age-associated decline in GFR. The finding is mainly observed in subjects with hypertension and/or renal failure but less in atherosclerotic subjects. Blood pressure was measured invasively in the ascending and abdominal aorta (at the level of kidneys) of 101 subjects undergoing coronary angiography. Independently of age, sex, and presence of coronary stenosis, amplification of PP between the ascending and terminal aorta was over 10 mm Hg (P<0.001), whereas mean blood pressure remained unchanged. Irrespective of PP measured in the ascending aorta and at the level of renal arteries, amplification was significantly related to proteinuria. Increased plasma creatinine and aortic pulse wave velocity were independently and positively correlated (P<0.001). The relationship between PP and renal function was mainly present in patients 60 years of age or older. Finally, renal transplant patients and their donors were recruited for evaluation of aortic stiffness and determination of the post-transplant decline trends in GFR. Determinants of filtration rate decline were evaluated at 1 year and at a mean of 9.2 ± 3.5 years after transplantation. The first year decline was related to smoking and acute rejection but the later decline was significantly and exclusively associated with donor age and aortic stiffness. In hypertensive humans, the significant association between PP and GFR indicates a cross-talk between the two parameters with arterial stiffness, and not vascular resistance, as major mediator.