Pulse transit time (PTT), is the time taken for a pressure wave generated by ventricular contraction to travel between two sites in the arterial tree. Changes in PTT reflect influences of the autonomic nervous system (ANS) on the peripheral circulation [1, 2]; an acute reduction in PTT reflects a stiffening of the arterial wall due to increased sympathetic tone. The present study uses simultaneous measurement of peripheral (PTTp) and central PTT (PTTc) to determine the effects of altered autonomic tone on peripheral and cerebral blood vessels. PTTp and PTTc (to the middle cerebral artery, MCA) were each determined in 12 healthy volunteers. The R wave of the electrocardiogram was used as an index of the aortic valve opening. The upstroke of the plethysmographic signal, from a finger pulse oximeter, marked the arrival of the pulse wave in the finger. The upstroke of the MCA blood flow velocity, determined using transcranial Doppler ultrasound, marked the arrival of the pressure wave in the MCA. The time delay between the R wave and each index determined PTTp and PTTc respectively. Three interventions known to induce ANS changes were applied 1) slow deep breathing (5 successive breaths), 2) Valsalva (for 10-15 secs) and 3) hand grip exercise (2 mins). For 1 & 2, the shortest and longest RR intervals were used to identify the extremes of ANS stimulation. For slow deep breathing, PTTp and PTTc both lengthened significantly during inspiration (shortest RR interval) when compared to expiration (longest RR interval). For the Valsalva, PTTp and PTTc were both significantly longer at the shortest RR interval, during the manoeuvre, compared with the longest RR interval immediately following the manoeuvre. Handgrip exercise significantly shortened RR interval, PTTp and PTTc, compared to rest. In conclusion, all three manoeuvres, producing changes in autonomic outflow, induced similar changes in PTT in the arterial circulations between the heart and the finger and the heart and the cerebral circulation suggesting that these two limbs of the circulation are under similar autonomic control.