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Recently Weber et al. invasively obtained aortic Pulse Wave Velocity (PWV) as a function of age. [1] Systolic and diastolic aortic pressure were determined as well. PWV can be used to derive total arterial compliance, Ctot, as Ctot=k/PWV2. With Ctot and Stroke Volume (SV), aortic Pulse Pressure (PP) can be approximated from Ctot=SV/PP. However, the PWV-derived value for Ctot predicted a larger PP increase with age than measured. [1] PWV increased from 5.6 to 12m/s between <40 and >80 years of age thus aortic compliance (Cao) decreased by a factor (12/5.6)2=4.6.[1] Setting Ctot equal to Cao, PP would increase by the same factor, while measured PP increased from 50 to 90 mmHg. SV decreasing with age may play a role but certainly not a factor 2. We hypothesize that Ctot is not equal to Cao as calculated form PWV: compliance of the conduit arteries, Cca, also contribute. This can be seen as follows. In the young Ctot=0.6, Cao=0.35 and Cca=0.25 (cgs units). At high age Cao reduces to 0.6/4.6=0.076 and Cca to 0.25/1.2=0.20, thus Ctot=0.28; about halved. PP then approximately doubles, in agreement with the pressure data. In aging Ctot decreases considerably less than Cao since the relatively smaller changes in Cca play a role as well. Changes in aortic PWV alone cannot predict the PP increase as a function of age.